CVE-2016-6458

What it is

A vulnerability in the content filtering functionality of Cisco AsyncOS Software for Cisco Email Security Appliances could allow an unauthenticated, remote attacker to bypass content filters configured on an affected device. Email that should have been filtered could instead be forwarded by the device. This vulnerability affects all releases prior to the first fixed release of Cisco AsyncOS Software for Cisco Email Security Appliances, both virtual and hardware appliances, if the software is configured to use a content filter for email attachments that are protected or encrypted. More Information: CSCva52546. Known Affected Releases: 10.0.0-125 9.7.1-066.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data tampering.

Exploit odds

2.2% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2016-11-19 03:03 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 00:51 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 2.2% in the next 30 days (EPSS).
• Severity: 7.5 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2016-11-19 03:03 UTC

Last modified

2026-06-17 00:51 UTC

Exploit probability

2.2% · EPSS, next 30 days

Weakness

CWE-20 · Improper input validation

Record status

Modified

Affected

• Cisco Email Security Appliance Firmware 9.7.1-066
• Cisco Email Security Appliance Firmware 9.7.2-046
• Cisco Email Security Appliance Firmware 9.7.2-047
• Cisco Email Security Appliance Firmware 9.7.2-054
• Cisco Email Security Appliance Firmware 9.9.6-026
• Cisco Email Security Appliance Firmware 9.9_base
• Cisco Email Security Appliance Firmware 10.0.0-124
• Cisco Email Security Appliance Firmware 10.0.0-125

Attack profile CVSS 3.0 · 7.5

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

High

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

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