CVE-2017-6627
Cisco IOS and Cisco IOS XE
Published 7 Sept 2017 · updated 17 Jun 2026 · Analyzed
Exploited in the wild
CISA added this to its Known Exploited Vulnerabilities catalog on 3 Mar 2022, with a remediation deadline of 24 Mar 2022 for US federal agencies.
Required action: Apply updates per vendor instructions.
Description
A vulnerability in the UDP processing code of Cisco IOS 15.1, 15.2, and 15.4 and IOS XE 3.14 through 3.18 could allow an unauthenticated, remote attacker to cause the input queue of an affected system to hold UDP packets, causing an interface queue wedge and a denial of service (DoS) condition. The vulnerability is due to Cisco IOS Software application changes that create UDP sockets and leave the sockets idle without closing them. An attacker could exploit this vulnerability by sending UDP packets with a destination port of 0 to an affected device. A successful exploit could allow the attacker to cause UDP packets to be held in the input interfaces queue, resulting in a DoS condition. The input interface queue will stop holding UDP packets when it receives 250 packets. Cisco Bug IDs: CSCup10024, CSCva55744, CSCva95506.
References
- www.securityfocus.com/bid/100644 · Broken Link, Third Party Advisory, VDB Entry
- www.securitytracker.com/id/1039289 · Broken Link, Third Party Advisory, VDB Entry
- tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170906-ios-udp · Mitigation, Vendor Advisory
- www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2017-6627 · US Government Resource