Cisco IOS Software for Cisco Integrated Services Routers Denial-of-Service Vulnerability

[ Why it matters ]Priority signals

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

[ Description ]Official description

A vulnerability in the implementation of a protocol in Cisco Integrated Services Routers Generation 2 (ISR G2) Routers running Cisco IOS 15.0 through 15.6 could allow an unauthenticated, adjacent attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. The vulnerability is due to a misclassification of Ethernet frames. An attacker could exploit this vulnerability by sending a crafted Ethernet frame to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition. Cisco Bug IDs: CSCvc03809.

CISA: A vulnerability in the implementation of a protocol in Cisco Integrated Services Routers Generation 2 (ISR G2) Routers running Cisco IOS could allow an unauthenticated, adjacent attacker to cause an affected device to reload, resulting in a denial of service.

[ Fixes ]Fixes and patches

CISA required action (US federal deadline 24 Mar 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

• www.securityfocus.com/bid/101044Broken LinkThird Party AdvisoryVDB Entry
• www.securitytracker.com/id/1039452Broken LinkThird Party AdvisoryVDB Entry
• tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170927-rbip-dosVendor Advisory
• www.cisa.gov/known-exploited-vulnerabilities-catalogUS Government Resource