PT-2009-4508 · Cisco · Cisco Ios Xr

Published 2009-08-18 · Updated 2025-10-22 · CVE-2009-2055

Positive Technologies (AI Summary)

CVSS v3.1

5.9

Medium

Base vector

AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions Cisco IOS XR versions 3.4.0 through 3.8.1

Description The issue allows remote attackers to cause a denial of service (session reset) via a BGP UPDATE message with an invalid attribute. This was demonstrated in the wild on 17 August 2009. The vulnerability manifests when a BGP peer announces a prefix with a specific invalid attribute, causing the Cisco IOS XR device to restart the peering session. Additionally, the Cisco IOS XR BGP process may crash when sending a long length BGP update message or when constructing a BGP update with a large number of AS prepends.

Recommendations For Cisco IOS XR versions 3.4.0 through 3.8.1, apply the free software maintenance upgrade (SMU) released by Cisco to address these vulnerabilities. As a temporary workaround, consider implementing workarounds that mitigate these vulnerabilities, such as restricting BGP update messages or limiting the number of AS prepends.

Fix

DoS

RCE

Weakness Enumeration

CWE-20

Related Identifiers

CVE-2009-2055

Affected Products

Cisco Ios Xr

References · 9

• https://nvd.nist.gov/vuln/detail/CVE-2009-2055 · Security Note
• http://cisco.com/en/US/products/products_security_advisory09186a0080af150f.shtml · Vendor Advisory
• https://cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2009-2055 · Note
• https://t.me/cvenotify/106429 · Telegram Post
• https://t.me/cveNotify/139761 · Telegram Post
• http://mailman.nanog.org/pipermail/nanog/2009-August/012719.html · Note
• https://t.me/cveNotify/139798 · Telegram Post
• http://securitytracker.com/id?1022739 · Note
• https://t.me/cveNotify/139721 · Telegram Post