Cisco IOS and IOS XE Software Improper Input Validation 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 DHCP option 82 encapsulation functionality of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. The vulnerability exists because the affected software performs incomplete input validation of option 82 information that it receives in DHCP Version 4 (DHCPv4) packets from DHCP relay agents. An attacker could exploit this vulnerability by sending a crafted DHCPv4 packet to an affected device. A successful exploit could allow the attacker to cause a heap overflow condition on the affected device, which will cause the device to reload and result in a DoS condition. Cisco Bug IDs: CSCvg62730.

CISA: A vulnerability in the DHCP option 82 encapsulation functionality of Cisco IOS Software and Cisco IOS XE Software could allow for denial-of-service (DoS).

[ Fixes ]Fixes and patches

CISA required action (US federal deadline 17 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/103552Third Party AdvisoryVDB Entry
• www.securitytracker.com/id/1040591Third Party AdvisoryVDB Entry
• ics-cert.us-cert.gov/advisories/ICSA-18-107-04Third Party AdvisoryUS Government Resource
• ics-cert.us-cert.gov/advisories/ICSA-18-107-05Third Party AdvisoryUS Government Resource
• tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180328-dhcpr1Vendor Advisory
• www.tenable.com/security/research/tra-2018-06Third Party Advisory
• www.cisa.gov/known-exploited-vulnerabilities-catalogUS Government Resource