CVE-2016-6474 Auth bypass in Cisco IOS

High 7.3 Published 14 Dec 2016 Updated 6 Aug 2024

Unauthenticated remote attackers can bypass SSH authentication in Cisco IOS and IOS XE due to flawed X.509 Version 3 implementation.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2016-6474?

CVE-2016-6474 is a high-severity authentication bypass vulnerability in Cisco Ios, published on 14 Dec 2016. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

A vulnerability in the implementation of X.509 Version 3 for SSH authentication functionality in Cisco IOS and IOS XE Software could allow an unauthenticated, remote attacker to bypass authentication on an affected system. More Information: CSCuv89417. Known Affected Releases: 15.5(2.25)T. Known Fixed Releases: 15.2(4)E1 15.2(4)E2 15.2(4)E3 15.2(4)EA4 15.2(4.0r)EB 15.2(4.1.27)EB 15.2(4.4.2)EA4 15.2(4.7.1)EC 15.2(4.7.2)EC 15.2(5.1.1)E 15.2(5.5.63)E 15.2(5.5.64)E 15.4(1)IA1.80 15.5(3)M1.1 15.5(3)M2 15.5(3)S1.4 15.5(3)S2 15.6(0.22)S0.12 15.6(1)T0.1 15.6(1)T1 15.6(1.15)T 15.6(1.17)S0.7 15.6(1.17)SP 15.6(1.22.1a)T0 15.6(2)S 15.6(2)SP 16.1(1.24) 16.1.2 16.2(0.247) 16.3(0.11) 3.8(1)E Denali-16.1.2.

Weakness: CWE-287

Which versions are affected by CVE-2016-6474?

It affects 1 product.

Products include Cisco Ios.

How do I fix CVE-2016-6474?

No fix has been published for CVE-2016-6474 yet. Limit exposure of the affected software until one is available.

Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.

Is CVE-2016-6474 being exploited?

There is no known exploitation of CVE-2016-6474 in the wild and no public exploit code.

All Cisco Ios vulnerabilities

Sources

Also known as GHSA-xqx5-4vvj-rqwr.