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UK Cyber Defence
VulnerabilityAnalyzed

CVE-2017-6627

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

KEVHIGH 7.5EPSS 6.04%

Does this matter?

Known to be exploited in the wild (CISA KEV, CISA remediation deadline 24 March 2022). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.

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.

CVSS 3.1
7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
6.04% probability · 93th percentile
CISA KEV
Listed 3 March 2022 · due 24 March 2022
Weakness
CWE-399, CWE-404
Affected
cisco/ios · cisco/ios xe
Source
psirt@cisco.com

CISA notes

Apply updates per vendor instructions. https://nvd.nist.gov/vuln/detail/CVE-2017-6627

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.