What is CVE-2016-6372?

CVE-2016-6372 is a high-severity vulnerability in Cisco Email Security Appliance, classified under Improper Input Validation. CVSS score: 7.5/10. Published 2016-10-28.

How severe is CVE-2016-6372?

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

Improper input validation in Cisco Email Security Appliance

CVE-2016-6372

A vulnerability in the email message and content filtering for malformed Multipurpose Internet Mail Extensions (MIME) headers of Cisco AsyncOS Software for Cisco Email Security Appliances (ESA) and Web Security Appliances (WSA) could allow an unauthenticated, remote attacker to bypass the filtering functionality of the targeted device. Emails that should have been quarantined could instead be processed. Affected Products: This vulnerability affects all releases prior to the first fixed release of Cisco AsyncOS Software for Cisco ESA and Cisco WSA on both virtual and hardware appliances that are configured with message or content filters to scan incoming email attachments. More Information: CSCuy54740, CSCuy75174. Known Affected Releases: 9.7.1-066 9.5.0-575 WSA10.0.0-000. Known Fixed Releases: 10.0.0-125 9.1.1-038 9.7.2-047.

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

Published 2016-10-28 · 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:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.016 (76.0th percentile), scored 2026-10-21.

Low probability of exploitation in the next 30 days, but still tracked. 76th percentile — 76.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.015 · newest: 0.016 · change: +0.001

Affected products

Cisco Email Security Appliance — versions 8.0.1-023, 8.0_base, 8.5.0-000
Cisco Web Security Appliance — versions 5.6.0-623, 6.0.0-000, 7.1.0
Cisco Web Security Appliance 8.0.5 — versions hot_patch_1
Cisco Asyncos Through Wsa10.0.0-000 — versions Cisco AsyncOS through WSA10.0.0-000

Weakness classification (CWE)

CWE-20 — Improper Input Validation

References

tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20161026… (Vendor Advisory)
www.securityfocus.com/bid/93911 (vdb-entry)
www.securitytracker.com/id/1037118 (vdb-entry)
www.securitytracker.com/id/1037119 (vdb-entry)

Frequently asked questions

What is CVE-2016-6372?: CVE-2016-6372 is a high-severity vulnerability in Cisco Email Security Appliance, classified under Improper Input Validation. CVSS score: 7.5/10. Published 2016-10-28.
How severe is CVE-2016-6372?: High severity. CVSS v3 base score is 7.5 out of 10.