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Table Of Contents
Cross-Platform Release Notes for Cisco IOS Release 12.3(4)TPC11
Resolved Caveats—Cisco IOS Release 12.3(4)TPC11B
Resolved Caveats—Cisco IOS Release 12.3(4)TPC11A
Cisco IOS Software Documentation Set
Obtaining Documentation, Obtaining Support, and Security Guidelines
Cross-Platform Release Notes for Cisco IOS Release 12.3(4)TPC11
August 6, 2007
Cisco IOS Release 12.3(4)TPC11B
OL-8202-03
This document lists the resolved caveat(s) for the Cisco SOHO 90 series routers and 831 series routers that support Cisco IOS Release 12.3T, up to and including Cisco IOS Release 12.3(4)TPC11A. Caveats describe unexpected behavior or defects in Cisco IOS software releases. Severity 1 caveats are the most serious caveats; severity 2 caveats are less serious.
To help us improve this document, please send us your comments. If you are reading Cisco product documentation on the World Wide Web, you can submit comments electronically at http://www.cisco.com/feedback/ or contact caveats-doc@cisco.com.
If You Need More Information
Cisco IOS software documentation can be found on the web through Cisco.com. For information on Cisco.com, see the "Obtaining Documentation, Obtaining Support, and Security Guidelines" section.
For more information on caveats and features in Cisco IOS Release 12.3T, refer to the following sources:
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Dictionary of Internetworking Terms and Acronyms—The Dictionary of Internetworking Terms and Acronyms contains definitions of acronyms that are not defined in this caveats document.
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Note
The most recent release notes document when this caveats document was published is Release Notes for Cisco IOS Release 12.3T, for Cisco IOS Release 12.3(14)T on May 2, 2005.
Hardware Supported
Cisco IOS Release 12.3(4)TPC11A supports the following Cisco routers:
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— Cisco SOHO 91 routers
— Cisco SOHO 96 routers
— Cisco SOHO 97 routers
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— Cisco 831 routers
— Cisco 836 routers
— Cisco 837 routers
Resolved Caveats—Cisco IOS Release 12.3(4)TPC11B
CSCsj66513 Traceback detected at DNQueuePeersSymptom Traceback found at DNQueuePeers
Conditions
Workaround
CSCdz55178 QoS profile name of more then 32 chars will crash the routerSymptom A router that is configured for QoS may reload unexpectedly or other serious symptoms such as memory corruption may occur.
Conditions
cable qos profile 12 name g711@10ms_for_any_softswitch_Traa^C00000000011111111111222222222333^12345678901234567890123456789012||PROBLEM(Variable Overflowed).Workaround
CSCsj66369 Traceback seen at rpmxf_dg_db_initSymptom Tracebacks seen while running metal_vpn_cases.itcl script
Conditions
Workaround
CSCed26739 mm/gk/gk_cli.c:CLI:gw-type-prefix possible buffer overflowSymptom The router will reload if "sh run" is given after a tech-prefix terminating with a large number of '.'s is configured as follows.
conf tgatekeepergw-type-prefix 1234......................................................Conditions
conf tgatekeepergw-type-prefix1234......................................................and enter command sh run
Workaround
CSCse85200 Inadequate validation of TLVs in cdpSymptom Specifically crafted CDP packets can cause a router to allocate and keep extra memory. Exploitation of this behaviour by sending multiple specifically crafted CDP packets could cause memory allocation problems on the router.
Conditions
Workaround
CSCef61610 Incorrect handling of ICMPv6 messages can cause TCP performance problemsA document that describes how the Internet Control Message Protocol (ICMP)could be used to perform a number of Denial of Service (DoS) attacks against the Transmission Control Protocol (TCP) has been made publicly available. This document has been published through the Internet Engineering Task Force (IETF) Internet Draft process, and is entitled "ICMP Attacks Against TCP".
(draft-gont-tcpm-icmp-attacks-03.txt).
These attacks, which only affect sessions terminating or originating on a device itself, can be of three types:
1.
2.
3.
Successful attacks may cause connection resets or reduction of throughput in existing connections, depending on the attack type. Multiple Cisco products are affected by the attacks described in this Internet draft.
Cisco has made free software available to address these vulnerabilities. In some cases there are workarounds available to mitigate the effects of the vulnerability.This advisory is posted at: http://www.cisco.com/warp/public/707/cisco-sa-20050412-icmp.shtml.
The disclosure of these vulnerabilities is being coordinated by the National Infrastructure Security Coordination Centre (NISCC), based in the United Kingdom. NISCC is working with multiple vendors whose products are potentially affected. Its posting can be found at: http://www.niscc.gov.uk/niscc/docs/re-20050412-00303.pdf?lang=en.
CSCed94829 IOS reloads due to malformed IKE messages.Multiple Cisco products contain vulnerabilities in the processing of IPSec IKE(Internet Key Exchange) messages. These vulnerabilities were identified by the University of Oulu Secure Programming Group (OUSPG) "PROTOS" Test Suite for IPSec and can be repeatedly exploited to produce a denial of service.
Cisco has made free software available to address this vulnerability for affected customers. Prior to deploying software, customers should consult their maintenance provider or check the software for feature set compatibility and known issues specific to their environment.This advisory is posted at: http://www.cisco.com/warp/customer/707/cisco-sa-20051114-ipsec.shtml.
CSCsb33172 short-circuit crypto engine operations when faking AM2A vulnerability exists in the way some Cisco products handle IKE phase I messages which allows an attacker to discover which group names are configured and valid on the device. A Cisco Security Notice has been published on this issue and can be found at the following URL: http://www.cisco.com/warp/public/707/cisco-sn-20050624-vpn-grpname.shtml.
CSCek37177 Malformed tcp packets deplete processor memory.The Cisco IOS Transmission Control Protocol (TCP) listener in certain versions of Cisco IOS software is vulnerable to a remotely-exploitable memory leak that may lead to a denial of service condition. This vulnerability only applies to traffic destined to the Cisco IOS device. Traffic transiting the Cisco IOS device will not trigger this vulnerability.Cisco has made free software available to address this vulnerability for affected customers. This issue is documented as Cisco bug ID CSCek37177
There are workarounds available to mitigate the effects of the vulnerability.This advisory is posted at: http://www.cisco.com/warp/public/707/cisco-sa-20070124-crafted-tcp.shtml.
CSCeh73049 tclsh mode bypasses aaa command authorization check.Symptom A vulnerability exists within the Cisco IOS Authentication, Authorization, and Accounting (AAA) command authorization feature, where command authorization checks are not performed on commands executed from the Tool Command Language (Tcl) exec shell. This may allow authenticated users to bypass command authorization checks in some configurations resulting in unauthorized privilege escalation.
Conditions
Workaround
CSCsd92405 Router crashed by repeated SSL connection with malformed finished messageCisco IOS device may crash while processing malformed Secure Sockets Layer (SSL) packets. In order to trigger these vulnerabilities, a malicious client must send malformed packets during the SSL protocol exchange with the vulnerable device.
Successful repeated exploitation of any of these vulnerabilities may lead to a sustained Denial-of-Service (DoS); however, vulnerabilities are not known to compromise either the confidentiality or integrity of the data or the device. These vulnerabilities are not believed to allow an attacker will not be able to decrypt any previously encrypted information.
Cisco IOS is affected by the following vulnerabilities:
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Cisco has made free software available to address these vulnerabilities for affected customers. There are workarounds available to mitigate the effects of these vulnerabilities.
This advisory is posted at: http://www.cisco.com/warp/public/707/cisco-sa-20070522-SSL.shtml
Note
A combined software table for Cisco IOS is available to aid customers in choosing a software releases that fixes all security vulnerabilities published as of May 22, 2007. This software table is available at the following link: http://www.cisco.com/warp/public/707/cisco-sa-20070522-cry-bundle.shtml.
CSCsb12598 Router forced crash on receiving fragmented TLS ClientHelloCisco IOS device may crash while processing malformed Secure Sockets Layer (SSL) packets. In order to trigger these vulnerabilities, a malicious client must send malformed packets during the SSL protocol exchange with the vulnerable device.
Successful repeated exploitation of any of these vulnerabilities may lead to a sustained Denial-of-Service (DoS); however, vulnerabilities are not known to compromise either the confidentiality or integrity of the data or the device. These vulnerabilities are not believed to allow an attacker will not be able to decrypt any previously encrypted information.
Cisco IOS is affected by the following vulnerabilities:
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Cisco has made free software available to address these vulnerabilities for affected customers. There are workarounds available to mitigate the effects of these vulnerabilities.
This advisory is posted at: http://www.cisco.com/warp/public/707/cisco-sa-20070522-SSL.shtml
Note
A combined software table for Cisco IOS is available to aid customers in choosing a software releases that fixes all security vulnerabilities published as of May 22, 2007. This software table is available at the following link: http://www.cisco.com/warp/public/707/cisco-sa-20070522-cry-bundle.shtml.CSCsb40304 Router crash on sending repetitive SSL ChangeCipherSpecCisco IOS device may crash while processing malformed Secure Sockets Layer (SSL) packets. In order to trigger these vulnerabilities, a malicious client must send malformed packets during the SSL protocol exchange with the vulnerable device.
Successful repeated exploitation of any of these vulnerabilities may lead to a sustained Denial-of-Service (DoS); however, vulnerabilities are not known to compromise either the confidentiality or integrity of the data or the device. These vulnerabilities are not believed to allow an attacker will not be able to decrypt any previously encrypted information.
Cisco IOS is affected by the following vulnerabilities:
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Cisco has made free software available to address these vulnerabilities for affected customers. There are workarounds available to mitigate the effects of these vulnerabilities.
This advisory is posted at: http://www.cisco.com/warp/public/707/cisco-sa-20070522-SSL.shtml
Note
A combined software table for Cisco IOS is available to aid customers in choosing a software releases that fixes all security vulnerabilities published as of May 22, 2007. This software table is available at the following link: http://www.cisco.com/warp/public/707/cisco-sa-20070522-cry-bundle.shtml.CSCsb11124 SGBP Crafted Packet Denial of ServiceThe Cisco IOS Stack Group Bidding Protocol (SGBP) feature in certain versions of Cisco IOS software is vulnerable to a remotely-exploitable denial of service condition. Devices that do not support or have not enabled the SGBP protocol are not affected by this vulnerability.
Cisco has made free software available to address this vulnerability for affected customers. There are workarounds available to mitigate the effects of the vulnerability. Cisco has published a Security Advisory on this issue; it is available at: http://www.cisco.com/warp/public/707/cisco-sa-20060118-sgbp.shtml
CSCse05736 A router running RCP can be reloaded with a specific packetSymptom A router that is running RCP can be reloaded by a specific packet.
Conditions
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Workaround
CSCsd85587 7200 Router crashes with ISAKMP Codenomicon test suiteA vulnerability has been discovered in a third party cryptographic library which is used by a number of Cisco products. This vulnerability may be triggered when a malformed Abstract Syntax Notation One (ASN.1) object is parsed. Due to the nature of the vulnerability it may be possible, in some cases, to trigger this vulnerability without a valid certificate or valid application-layer credentials (such as a valid username or password).
Successful repeated exploitation of any of these vulnerabilities may lead to a sustained Denial-of-Service (DoS); however, vulnerabilities are not known to compromise either the confidentiality or integrity of the data or the device. These vulnerabilities are not believed to allow an attacker will not be able to decrypt any previously encrypted information.
The vulnerable cryptographic library is used in the following Cisco products:
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This vulnerability is also being tracked by CERT/CC as VU#754281.
Cisco has made free software available to address this vulnerability for affected customers. There are no workarounds available to mitigate the effects of the vulnerability. This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20070522-crypto.shtml.
Note
at: http://www.cisco.com/warp/public/707/cisco-sa-20070522-cry-bundle.shtml and can be used to choose a software release which fixes all security vulnerabilities published as of May 22, 2007. The related advisory is published at http://www.cisco.com/warp/public/707/cisco-sa-20070522-SSL.shtml.CSCee41508 RSVP red zone crashSymptom An IOS device may crash when processing a malformed Resource ReSerVation Protocol (RSVP) packet.
Conditions
Workaround
CSCef48336 Corrupted OSPF Hello packets caused software forced crashOSPF is a routing protocol defined by RFC 2328. It is designed to manage IP routing inside an Autonomous System (AS). OSPF packets use IP protocol number 89. A vulnerability exists in the processing of an OSPF packet that can be exploited to cause the reload of a system.
Since OSPF needs to process unicast packets as well as multicast packets, this vulnerability can be exploited remotely. It is also possible for an attacker to target multiple systems on the local segment at a time.
Using OSPF Authentication can be used to mitigate the effects of this vulnerability. Using OSPF Authentication is a highly recommended security best practice. A Cisco device receiving a malformed OSPF packet will reset and may take several minutes to become fully functional. This vulnerability may be exploited repeatedly resulting in an extended DOS attack.
Workaround
Refer to http://www.cisco.com/warp/public/104/25.shtml for more information about OSPF authentication. Infrastructure Access Control Lists Although it is often difficult to block traffic transiting your network, it is possible to identify traffic which should never be allowed to target your infrastructure devices and block that traffic at the border of your network. Infrastructure ACLs are considered a network security best practice and should be considered as a long-term addition to good network security as well as a workaround for this specific vulnerability. The white paper "Protecting Your Core: Infrastructure Protection Access Control Lists" presents guidelines and recommended deployment techniques for infrastructure protection ACLs: http://www.cisco.com/warp/public/707/iacl.html
CSCsc72722 CBAC - firewall resets TCP idle timer upon receiving invalid TCP packets.Symptom TCP connections that are opened through a Cisco IOS Firewall (CBAC) may not timeout.
Conditions
Workaround
CSCsg16908 IOS FTP server deprecation:Multiple vulnerabilities exist in the Cisco IOS File Transfer Protocol (FTP) Server feature. These vulnerabilities include Denial of Service, improper verification of user credentials and the ability to read or write any file in the device's filesystem, including the device's saved configuration, which may include passwords or other sensitive information.
The IOS FTP Server is an optional service that is disabled by default. Devices that are not specifically configured to enable the IOS FTP Server service are unaffected by these vulnerabilities.
This vulnerability does not apply to the IOS FTP Client feature.
This advisory is posted at: http://www.cisco.com/warp/public/707/cisco-sa-20070509-iosftp.shtml
CSCsb93407 H323 port tcp 1720 still listening after call service stopSymptom When H323 call service stops, the router still listens on TCP port 1720 and completes connection attempts.
Conditions
voice service voip
h323
call service stop
Workaround
For further information about deploying access lists, see the "Protecting Your Core: Infrastructure Protection Access Control Lists" document at: http://www.cisco.com/warp/public/707/iacl.html.
For information about using control plane policing to block access to TCP port 1720, see the "Deploying Control Plane Policing White Paper" at: http://www.cisco.com/en/US/products/ps6642/products_white_paper0900aecd804fa16a.shtml.
CSCsf28840 Crash due to configured peer type control vectorA vulnerability exists in the Data-link Switching (DLSw) feature in Cisco IOS where an invalid value in a DLSw message could result in a reload of the DLSw device. Successful exploitation of this vulnerability requires that an attacker be able to establish a DLSw connection to the device.
There are workarounds available for this vulnerability.
This advisory is posted at: http://www.cisco.com/warp/public/707/cisco-sa-20070110-dlsw.shtml
CSCsb11849 CoPP: Need support for malformed IP optionsSymptom CoPP policy configured to drop packets with IP options will ignore packets with malformed IP options.
Conditions
Workaround
CSCse24889 Malformed SSH version 2 packets may cause processor memory depletionSymptom Malformed SSH version 2 packets may cause a memory leak, causing the platform to operate under a degraded condition. Under rare circumstances, the platform may reload to recover itself.
Conditions
Workaround
config tip ssh version 1 endAlternate Workaround: Permit only known trusted hosts and/or networks to connect to the router by creating a vty access list, as in the following example:
10.1.1.0/24 is a trusted network that is permitted access to the router, all other access is denied access-list 99 permit 10.1.1.0 0.0.0.255 access-list 99 deny any line vty 0 4 access-class 99 in endFurther Problem Description : For information about configuring vty access lists, see the Controlling Access to a Virtual Terminal Line document: http://www.cisco.com/en/US/products/ps6441/products_configuration_guide_chapter09186a0080716ec2.html
For information about SSH, see the Configuring Secure Shell on Routers and Switches Running Cisco IOS document: http://www.cisco.com/warp/public/707/ssh.shtml.
CSCsa54608 IOS Firewall Auth-Proxy for FTP/Telnet Sessions buffer overflowThe Cisco IOS Firewall Authentication Proxy for FTP and/or Telnet Sessions feature in specific versions of Cisco IOS software is vulnerable to a remotely-exploitable buffer overflow condition. Devices that do not support, or are not configured for Firewall Authentication Proxy for FTP and/or Telnet Services are not affected.
Devices configured with only Authentication Proxy for HTTP and/or HTTPS are not affected. Only devices running certain versions of Cisco IOS are affected. Cisco has made free software available to address this vulnerability. There are workarounds available to mitigate the effects of the vulnerability. This advisory will be posted at: http://www.cisco.com/warp/public/707/cisco-sa-20050907-auth_proxy.shtml
CSCee45312 Radius authentication bypass when configured with a none fallback methodRemote Authentication Dial In User Service (RADIUS) authentication on a device that is running certain versions of Cisco Internetworking Operating System (IOS) and configured with a fallback method to none can be bypassed. Systems that are configured for other authentication methods or that are not configured with a fallback method to none are not affected.
Only the systems that are running certain versions of Cisco IOS are affected. Not all configurations using RADIUS and none are vulnerable to this issue. Some configurations using RADIUS, none and an additional method are not affected.
Cisco has made free software available to address this vulnerability. There are workarounds available to mitigate the effects of the vulnerability.
More details can be found in the security advisory which posted at the following URL: http://www.cisco.com/warp/public/707/cisco-sa-20050629-aaa.shtml
CSCin95836 Buffer overflow in NHRP protocolSymptom A Cisco IOS device configured for NHRP may restart.
Workaround
CSCei61732 Additional data integrity check in system timerCisco IOS may permit arbitrary code execution after exploitation of a heap-based buffer overflow vulnerability. Cisco has included additional integrity checks in its software, as further described below, that are intended to reduce the likelihood of arbitrary code execution.
Cisco has made free software available that includes the additional integrity checks for affected customers.
This advisory is posted at: http://www.cisco.com/warp/public/707/cisco-sa-20051102-timers.shtml
CSCek26492 Enhancements to Packet Input Path.Symptom A router may crash if it receives a packet with a specific crafted IP option as detailed in Cisco Security Advisory: Crafted IP Option Vulnerability: http://www.cisco.com/warp/public/707/cisco-sa-20070124-crafted-ip-option.shtml
Conditions
Workaround
CSCec71950 Crafted IP Option may cause DoS or code execution.Cisco routers and switches running Cisco IOS or Cisco IOS XR software may be vulnerable to a remotely exploitable crafted IP option Denial of Service (DoS) attack. Exploitation of the vulnerability may potentially allow for arbitrary code execution. The vulnerability may be exploited after processing an Internet Control Message Protocol (ICMP) packet, Protocol Independent Multicast version 2 (PIMv2) packet, Pragmatic General Multicast (PGM) packet, or URL Rendezvous Directory (URD) packet containing a specific crafted IP option in the packet's IP header. No other IP protocols are affected by this issue.
Cisco has made free software available to address this vulnerability for affected customers. There are workarounds available to mitigate the effects of the vulnerability. This vulnerability was discovered during internal testing. This advisory is available at:
http://www.cisco.com/warp/public/707/cisco-sa-20070124-crafted-ip-option.shtml
Resolved Caveats—Cisco IOS Release 12.3(4)TPC11A
Cisco IOS Release 12.3(4)TPC11A is a rebuild release for Cisco IOS Release 12.3(4)TPC11. The caveats in this section are resolved in Cisco IOS Release 12.3(4)TPC11A but may be open in previous Cisco IOS releases.
Basic System Services
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Cisco IOS may permit arbitrary code execution after exploitation of a heap-based buffer overflow vulnerability. Cisco has included additional integrity checks in its software, as further described below, that are intended to reduce the likelihood of arbitrary code execution.
Cisco has made free software available that includes the additional integrity checks for affected customers.
This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20051102-timers.shtml
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Remote Authentication Dial In User Service (RADIUS) authentication on a device that is running certain versions of Cisco Internetworking Operating System (IOS) and configured with a fallback method of none can be bypassed.
Systems that are configured for other authentication methods or that are not configured with a fallback method of none are not affected.
Only the systems that are running certain versions of Cisco IOS are affected. Not all configurations using RADIUS and fallback method of none are vulnerable to this issue. Some configurations using RADIUS, fallback method of none, and an additional method are not affected.
Cisco has made free software available to address this vulnerability. There are workarounds available to mitigate the effects of the vulnerability.
More details can be found in the security advisory which is posted at the following URL http://www.cisco.com/warp/public/707/cisco-sa-20050629-aaa.shtml.
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Symptom: Informs can't be sourced from a particular interface.
Conditions: The user is using informs and wants them to go out on a particular interface.
Workaround: There is no workaround.
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Symptom: Although there are free tty lines, the user cannot make a Telnet connection and a "No Free TTYs Error" message is generated.
Conditions: This symptom is observed when there are simultaneous Telnet requests.
Workaround: There is no workaround.
IP Routing Protocols
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OSPF is a routing protocol defined by RFC 2328. It is designed to manage IP routing inside an Autonomous System (AS). OSPF packets use IP protocol number 89.
A vulnerability exists in the processing of an OSPF packet that can be exploited to cause the reload of a system.
Since OSPF needs to process unicast packets as well as multicast packets, this vulnerability can be exploited remotely. It is also possible for an attacker to target multiple systems on the local segment at a time.
Using OSPF Authentication can be used to mitigate the effects of this vulnerability. Using OSPF Authentication is a highly recommended security best practice
A Cisco device receiving a malformed OSPF packet will reset and may take several minutes to become fully functional. This vulnerability may be exploited repeatedly resulting in an extended DOS attack.
Workarounds: Using OSPF Authentication
OSPF authentication may be used as a workaround. OSPF packets without a valid key will not be processed. MD5 authentication is highly recommended, due to inherent weaknesses in plain text authentication. With plain text authentication, the authentication key will be sent unencrypted over the network, which can allow an attacker on a local network segment to capture the key by sniffing packets.
Refer to http://www.cisco.com/warp/public/104/25.shtml for more information about OSPF authentication.
Infrastructure Access Control Lists
Although it is often difficult to block traffic transiting your network, it is possible to identify traffic which should never be allowed to target your infrastructure devices and block that traffic at the border of your network. Infrastructure ACLs are considered a network security best practice and should be considered as a long-term addition to good network security as well as a workaround for this specific vulnerability. The white paper "Protecting Your Core: Infrastructure Protection Access Control Lists" presents guidelines and recommended deployment techniques for infrastructure protection ACLs: http://www.cisco.com/warp/public/707/iacl.html
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A document that describes how the Internet Control Message Protocol (ICMP) could be used to perform a number of Denial of Service (DoS) attacks against the Transmission Control Protocol (TCP) has been made publicly available. This document has been published through the Internet Engineering Task Force (IETF) Internet Draft process, and is entitled "ICMP Attacks Against TCP" (draft-gont-tcpm-icmp-attacks-03.txt).
These attacks, which only affect sessions terminating or originating on a device itself, can be of three types:
1. Attacks that use ICMP "hard" error messages.
2. Attacks that use ICMP "fragmentation needed and Don't Fragment (DF) bit set" messages, also known as Path Maximum Transmission Unit Discovery (PMTUD) attacks.
3. Attacks that use ICMP "source quench" messages.
Successful attacks may cause connection resets or reduction of throughput in existing connections, depending on the attack type.
Multiple Cisco products are affected by the attacks described in this Internet draft.
Cisco has made free software available to address these vulnerabilities. In some cases there are workarounds available to mitigate the effects of the vulnerability.
This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20050412-icmp.shtml.
The disclosure of these vulnerabilities is being coordinated by the National Infrastructure Security Coordination Centre (NISCC), based in the United Kingdom. NISCC is working with multiple vendors whose products are potentially affected. Its posting can be found at: http://www.niscc.gov.uk/niscc/docs/re-20050412-00303.pdf?lang=en.
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A document that describes how the Internet Control Message Protocol (ICMP) could be used to perform a number of Denial of Service (DoS) attacks against the Transmission Control Protocol (TCP) has been made publicly available. This document has been published through the Internet Engineering Task Force (IETF) Internet Draft process, and is entitled "ICMP Attacks Against TCP" (draft-gont-tcpm-icmp-attacks-03.txt).
These attacks, which only affect sessions terminating or originating on a device itself, can be of three types:
1. Attacks that use ICMP "hard" error messages.
2. Attacks that use ICMP "fragmentation needed and Don't Fragment (DF) bit set" messages, also known as Path Maximum Transmission Unit Discovery (PMTUD) attacks.
3. Attacks that use ICMP "source quench" messages.
Successful attacks may cause connection resets or reduction of throughput in existing connections, depending on the attack type.
Multiple Cisco products are affected by the attacks described in this Internet draft.
Cisco has made free software available to address these vulnerabilities. In some cases there are workarounds available to mitigate the effects of the vulnerability.
This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20050412-icmp.shtml.
The disclosure of these vulnerabilities is being coordinated by the National Infrastructure Security Coordination Centre (NISCC), based in the United Kingdom. NISCC is working with multiple vendors whose products are potentially affected. Its posting can be found at: http://www.niscc.gov.uk/niscc/docs/re-20050412-00303.pdf?lang=en.
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A document that describes how the Internet Control Message Protocol (ICMP) could be used to perform a number of Denial of Service (DoS) attacks against the Transmission Control Protocol (TCP) has been made publicly available. This document has been published through the Internet Engineering Task Force (IETF) Internet Draft process, and is entitled "ICMP Attacks Against TCP" (draft-gont-tcpm-icmp-attacks-03.txt).
These attacks, which only affect sessions terminating or originating on a device itself, can be of three types:
1. Attacks that use ICMP "hard" error messages.
2. Attacks that use ICMP "fragmentation needed and Don't Fragment (DF) bit set" messages, also known as Path Maximum Transmission Unit Discovery (PMTUD) attacks.
3. Attacks that use ICMP "source quench" messages.
Successful attacks may cause connection resets or reduction of throughput in existing connections, depending on the attack type.
Multiple Cisco products are affected by the attacks described in this Internet draft.
Cisco has made free software available to address these vulnerabilities. In some cases there are workarounds available to mitigate the effects of the vulnerability.
This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20050412-icmp.shtml.
The disclosure of these vulnerabilities is being coordinated by the National Infrastructure Security Coordination Centre (NISCC), based in the United Kingdom. NISCC is working with multiple vendors whose products are potentially affected. Its posting can be found at: http://www.niscc.gov.uk/niscc/docs/re-20050412-00303.pdf?lang=en.
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A document that describes how the Internet Control Message Protocol (ICMP) could be used to perform a number of Denial of Service (DoS) attacks against the Transmission Control Protocol (TCP) has been made publicly available. This document has been published through the Internet Engineering Task Force (IETF) Internet Draft process, and is entitled "ICMP Attacks Against TCP" (draft-gont-tcpm-icmp-attacks-03.txt).
These attacks, which only affect sessions terminating or originating on a device itself, can be of three types:
1. Attacks that use ICMP "hard" error messages.
2. Attacks that use ICMP "fragmentation needed and Don't Fragment (DF) bit set" messages, also known as Path Maximum Transmission Unit Discovery (PMTUD) attacks.
3. Attacks that use ICMP "source quench" messages.
Successful attacks may cause connection resets or reduction of throughput in existing connections, depending on the attack type.
Multiple Cisco products are affected by the attacks described in this Internet draft.
Cisco has made free software available to address these vulnerabilities. In some cases there are workarounds available to mitigate the effects of the vulnerability.
This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20050412-icmp.shtml.
The disclosure of these vulnerabilities is being coordinated by the National Infrastructure Security Coordination Centre (NISCC), based in the United Kingdom. NISCC is working with multiple vendors whose products are potentially affected. Its posting can be found at: http://www.niscc.gov.uk/niscc/docs/re-20050412-00303.pdf?lang=en.
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A document that describes how the Internet Control Message Protocol (ICMP) could be used to perform a number of Denial of Service (DoS) attacks against the Transmission Control Protocol (TCP) has been made publicly available. This document has been published through the Internet Engineering Task Force (IETF) Internet Draft process, and is entitled "ICMP Attacks Against TCP" (draft-gont-tcpm-icmp-attacks-03.txt).
These attacks, which only affect sessions terminating or originating on a device itself, can be of three types:
1. Attacks that use ICMP "hard" error messages.
2. Attacks that use ICMP "fragmentation needed and Don't Fragment (DF) bit set" messages, also known as Path Maximum Transmission Unit Discovery (PMTUD) attacks.
3. Attacks that use ICMP "source quench" messages.
Successful attacks may cause connection resets or reduction of throughput in existing connections, depending on the attack type.
Multiple Cisco products are affected by the attacks described in this Internet draft.
Cisco has made free software available to address these vulnerabilities. In some cases there are workarounds available to mitigate the effects of the vulnerability.
This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20050412-icmp.shtml.
The disclosure of these vulnerabilities is being coordinated by the National Infrastructure Security Coordination Centre (NISCC), based in the United Kingdom. NISCC is working with multiple vendors whose products are potentially affected. Its posting can be found at: http://www.niscc.gov.uk/niscc/docs/re-20050412-00303.pdf?lang=en.
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Symptom: A router may reset its Border Gateway Protocol (BGP) session.
Conditions: This symptom is observed when a Cisco router that peers with other routers receives an Autonomous System (AS) path with a length that is equal to or greater than 255.
Workaround: Configure the bgp maxas limit command in such as way that the maximum length of the AS path is a value below 255. When the router receives an update with an excessive AS path value, the prefix is rejected, and the event recorded in the log.
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A document that describes how the Internet Control Message Protocol (ICMP) could be used to perform a number of Denial of Service (DoS) attacks against the Transmission Control Protocol (TCP) has been made publicly available. This document has been published through the Internet Engineering Task Force (IETF) Internet Draft process, and is entitled "ICMP Attacks Against TCP" (draft-gont-tcpm-icmp-attacks-03.txt).
These attacks, which only affect sessions terminating or originating on a device itself, can be of three types.
1. Attacks that use ICMP "hard" error messages.
2. Attacks that use ICMP "fragmentation needed and Don't Fragment (DF) bit set" messages, also known as Path Maximum Transmission Unit Discovery (PMTUD) attacks.
3. Attacks that use ICMP "source quench" messages.
Successful attacks may cause connection resets or reduction of throughput in existing connections, depending on the attack type.
Multiple Cisco products are affected by the attacks described in this Internet draft.
Cisco has made free software available to address these vulnerabilities. In some cases there are workarounds available to mitigate the effects of the vulnerability.
This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20050412-icmp.shtml.
The disclosure of these vulnerabilities is being coordinated by the National Infrastructure Security Coordination Centre (NISCC), based in the United Kingdom. NISCC is working with multiple vendors whose products are potentially affected. Its posting can be found at: http://www.niscc.gov.uk/niscc/docs/re-20050412-00303.pdf?lang=en.
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Configuring multiple static NAT translations with the extendable keyword results in only the first entry being installed in the running configuration.
Workaround: There is no workaround.
Wide Area Networking
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Symptom: An ISDN link on a BRI interface may fial to establish itself, and a ping may fail.
Conditions: This symptom is observed when the BRI link is connnected through an ISDN simulator.
Workaround: There is no workaround.
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A document that describes how the Internet Control Message Protocol (ICMP) could be used to perform a number of Denial of Service (DoS) attacks against the Transmission Control Protocol (TCP) has been made publicly available. This document has been published through the Internet Engineering Task Force (IETF) Internet Draft process, and is entitled "ICMP Attacks Against TCP"
These attacks, which only affect sessions terminating or originating on a device itself, can be of three types:
1. Attacks that use ICMP "hard" error messages.
2. Attacks that use ICMP "fragmentation needed and Don't Fragment (DF) bit set" messages, also known as Path Maximum Transmission Unit Discovery (PMTUD) attacks.
3. Attacks that use ICMP "source que3nch" messages. Successful attacks may cause connection resets or reduction of throughput in existing connections, depending on the attack type.
Multiple Cisco products are affected by the attacks described. Cisco has made available free software to address these vulnerabilities. In some cases, there are workarounds available to mitigate the effects of the vulnerability.
This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20050412-icmp.shtml. The disclosure of these vulnerabilities is being coordinated by the National Infrastructure Security Coordination Centre (NISCC), based in the United Kingdom. NISCC is working with multiple vendors whose products are potentially affected. It's posting can be found at: http://www.nis-cc.gov.uk/nis-cc/docs/re-20050412-00303/pdf?lang=en.
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Symptoms: Radius Attribute 61 (NAS-PORT-TYPE) is incorrectly reported as "Virtual" to radius instead of "ASYNC" or ISND."
Conditions: This symptom occurs when using a non-Cisco L2TP Access Concentrator (LAC) that does not support draft 1 or higher of RFC2661 in a VPDN setup with a Cisco 7200 multihop node.
Workaround: There is no workaround.
Miscellaneous
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The Cisco IOS Firewall Authentication Proxy for FTP and/or Telnet Sessions feature in specific versions of Cisco IOS software is vulnerable to a remotely-exploitable buffer overflow condition.
Devices that do not support, or are not configured for Firewall Authentication Proxy for FTP and/or Telnet Services are not affected.
Devices configured with only Authentication Proxy for HTTP and/or HTTPS are not affected.
Only devices running certain versions of Cisco IOS are affected.
Cisco has made free software available to address this vulnerability. There are workarounds available to mitigate the effects of the vulnerability.
This advisory will be posted at http://www.cisco.com/warp/public/707/cisco-sa-20050907-auth_proxy.shtml
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Symptoms: CBAC sessions left in sis-closing state due to out-of-order packet handling.
Workaround: There is no workaround. Lowering the inspect FTP timeout will reduce exposure. Disabling CEF will reduce exposure.
Fix: Bump certain out-of-order packets to process path for catch-up and then drop packets if unsuccessful.
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Cisco products running IOS contain vulnerabilities in the processing of H.323 messages, which are typically used in packetized voice or multimedia applications. Features such as NAT and IOS Firewall must inspect H.323 messages and may be vulnerable as well. A test suite has been developed by the University of Oulu to target this protocol and identify vulnerabilities.
Support for the H.323 protocol was introduced in Cisco IOS Software Release 11.3T, and all later Cisco IOS releases are affected if configured for various types of Voice/Multimedia Application support. The vulnerabilities can be exploited repeatedly to produce a denial of service (DoS).
There are workarounds available that may mitigate the impact, but these techniques may not be appropriate for use in all customer networks.
This advisory is available at http://www.cisco.com/warp/public/707/cisco-sa-20040113-h323.shtml.
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Symptom: The HEX representation of ALERTING TPKT is not sent in a voice call with PI value 8 being sent.
Workaround: There is no workaround.
Additional References
The following sections describe the documentation available for the Cisco 1700 series routers. These documents consist of hardware and software installation guides, Cisco IOS configuration guides and command references, system error messages, feature modules, and other documents.
Documentation is available as printed manuals or electronic documents, except for feature modules, which are available online on Cisco.com and http://www.cisco.com/univercd/home/index.htm.
Use these release notes with these documents:
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Release-Specific Documents
The following documents are specific to Cisco IOS Release 12.3 and are located on Cisco.com and http://www.cisco.com/univercd/home/index.htm:
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Note
•
http://www.cisco.com/univercd/home/index.htm
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As a supplement to the caveats listed in these release notes, see Caveats for Cisco IOS Release 12.3 and Caveats for Cisco IOS Release 12.3T, which contain caveats applicable to all platforms for all maintenance releases of Cisco IOS Release 12.3 and Cisco IOS Release 12.3T.
•
Platform-Specific Documents
These documents are available for the Cisco 1700 series routers:
On Cisco.com at: http://www.cisco.com/univercd/home/index.htm
Cisco IOS Software Documentation Set
The Cisco IOS software documentation set consists of the Cisco IOS configuration guides, Cisco IOS command references, and several other supporting documents.
Documentation Modules
Each module in the Cisco IOS documentation set consists of one or more configuration guides and one or more corresponding command references. Chapters in a configuration guide describe protocols, configuration tasks, and Cisco IOS software functionality, and contain comprehensive configuration examples. Chapters in a command reference provide complete command syntax information. Use each configuration guide with its corresponding command reference. Cisco IOS Software Documentation is available in html or pdf form.
Select your release and click the command references, configuration guides, or any other Cisco IOS documentation you need.
Obtaining Documentation, Obtaining Support, and Security Guidelines
For information on obtaining documentation, obtaining support, providing documentation feed-back, security guidelines, and also recommended aliases and general Cisco documents, see the monthly What's New in Cisco Product Documentation, which also lists all new and revised Cisco technical documentation at:
http://www.cisco.com/en/US/docs/general/whatsnew/whatsnew.htmlCisco.com
Use this document in conjunction with the documents listed in the " Additional References" section.
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Posted: Mon Aug 6 10:27:09 PDT 2007
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