Cisco IOS XR Border Gateway Protocol (BGP) Denial-of-Service Vulnerability

[ Why it matters ]Priority signals

• Exploited in the wild: on CISA's Known Exploited Vulnerabilities list since 2022-03-25

[ Description ]Official description

Cisco IOS XR 3.4.0 through 3.9.1, when BGP is enabled, does not properly handle unrecognized transitive attributes, which allows remote attackers to cause a denial of service (peering reset) via a crafted prefix announcement, as demonstrated in the wild in August 2010 with attribute type code 99, aka Bug ID CSCti62211.

CISA: Cisco IOS XR, when BGP is the configured routing feature, allows remote attackers to cause a denial-of-service (DoS).

[ Fixes ]Fixes and patches

CISA required action (US federal deadline 15 Apr 2022): Apply updates per vendor instructions.

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ References ]References

• mailman.nanog.org/pipermail/nanog/2010-August/024837.htmlMailing List
• osvdb.org/67696Broken Link
• secunia.com/advisories/41190Broken Link
• www.cisco.com/en/US/products/products_security_advisory09186a0080b4411f.shtmlBroken LinkVendor Advisory
• www.securitytracker.com/idBroken LinkThird Party AdvisoryVDB Entry
• www.vupen.com/english/advisories/2010/2227Broken Link
• exchange.xforce.ibmcloud.com/vulnerabilities/61443VDB EntryVendor Advisory
• www.cisa.gov/known-exploited-vulnerabilities-catalogUS Government Resource