What is CVE-2016-6431?

CVE-2016-6431 is a high-severity vulnerability in Cisco Adaptive Security Appliance Software, classified under Improper Input Validation. CVSS score: 7.5/10. Published 2016-10-27.

How severe is CVE-2016-6431?

High severity. CVSS v3 base score is 7.5 out of 10.

Improper input validation in Cisco Adaptive Security Appliance Software

CVE-2016-6431

A vulnerability in the local Certificate Authority (CA) feature of Cisco ASA Software before 9.6(1.5) could allow an unauthenticated, remote attacker to cause a reload of the affected system. The vulnerability is due to improper handling of crafted packets during the enrollment operation. An attacker could exploit this vulnerability by sending a crafted enrollment request to the affected system. An exploit could allow the attacker to cause the reload of the affected system. Note: Only HTTPS packets directed to the Cisco ASA interface, where the local CA is allowing user enrollment, can be used to trigger this vulnerability. This vulnerability affects systems configured in routed firewall mode and in single or multiple context mode.

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

Published 2016-10-27 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.025 (84.4th percentile), scored 2026-10-02.

Low probability of exploitation in the next 30 days, but still tracked. 84th percentile — 84.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.025 · newest: 0.025 · change: 0.000

Affected products

Cisco Adaptive Security Appliance Software — versions 8.1.2.13, 9.1\(7\)6, 9.4.3.4
Cisco Asa Software Before 9.6(1.5) — versions Cisco ASA Software before 9.6(1.5)

Weakness classification (CWE)

CWE-20 — Improper Input Validation

References

www.securityfocus.com/bid/93786 (VDB Entry, Third Party Advisory, vdb-entry)
tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20161019… (Vendor Advisory)
www.securitytracker.com/id/1037060 (vdb-entry)

Frequently asked questions

What is CVE-2016-6431?: CVE-2016-6431 is a high-severity vulnerability in Cisco Adaptive Security Appliance Software, classified under Improper Input Validation. CVSS score: 7.5/10. Published 2016-10-27.
How severe is CVE-2016-6431?: High severity. CVSS v3 base score is 7.5 out of 10.