CVE-2017-6627

KEVCisco IOS Software and Cisco IOS XE Software UDP Packet Processing Denial-of-Service Vulnerability

Description

A vulnerability in the UDP processing code of Cisco IOS and IOS XE 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 denial of service.

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.

CVSS 3.1 vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

PublishedSep 7, 2017

Last modifiedJun 17, 2026

Added to KEVMar 3, 2022

Remediation dueMar 24, 2022

References

securityfocus.com/bid/100644Broken LinkThird Party Advisory
securitytracker.com/id/1039289Broken LinkThird Party Advisory
tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170906-ios-udpMitigationVendor Advisory
cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2017-6627US Government Resource

0 recent articles mention this CVE

Risk assessment · High

Actively exploited. Patch immediately.

Exploitation: Confirmed in the wild (CISA KEV)
Federal remediation deadline: Overdue by 1678 days
CVSS: 7.5 HIGH
EPSS (30-day exploit probability): 6.2% · top 7% of all CVEs
Weakness: CWE-399
Attack vector: Network, remotely reachable
Preconditions: No privileges and no user interaction

Recommended actions

1.Apply updates per vendor instructions.
2.Treat as emergency change: patch or isolate internet-facing instances first.
3.Review exposure: confirm which instances are reachable from the internet and restrict access until patched.
4.Hunt for compromise: review logs for the disclosure window, not just from the patch date.

Assessment is derived automatically from the live signals above; verify against your own asset inventory.