CVE-2016-6463

A vulnerability in the email filtering functionality of Cisco AsyncOS Software for Cisco Email Security Appliances could allow an unauthenticated, remote attacker to bypass Advanced Malware Protection (AMP) filters that are configured for an affected device. This vulnerability affects all releases prior to the first fixed release of Cisco AsyncOS Software for both virtual and hardware versions of Cisco Email Security Appliances, if the AMP feature is configured to scan incoming email attachments. More Information: CSCuz85823. Known Affected Releases: 10.0.0-082 9.7.0-125 9.7.1-066. Known Fixed Releases: 10.0.0-203 9.7.2-131.

Published: 2016-11-18 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2016-6463 is rated Moderate Risk (43.9/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.13%). Mandatory action: Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2016-6463

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.18% 1.13% +0.95%
2 2025-03-17 0.13% 0.18% +0.05%
3 2023-03-07 0.13%

Full EPSS history (4 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2016-6463

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.3 3.0 MEDIUM
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
3.9 1.4 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:P/I:N/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
10.0 2.9 [email protected]

Weakness enumeration for CVE-2016-6463

Affected software / configurations for CVE-2016-6463

Vendor Product Version Raw CPE
cisco email_security_appliance_firmware 9.7.0-125 cpe:2.3:o:cisco:email_security_appliance_firmware:9.7.0-125:*:*:*:*:*:*:*
cisco email_security_appliance_firmware 9.7.1-06 cpe:2.3:o:cisco:email_security_appliance_firmware:9.7.1-06:*:*:*:*:*:*:*
cisco email_security_appliance_firmware 10.0.0-082 cpe:2.3:o:cisco:email_security_appliance_firmware:10.0.0-082:*:*:*:*:*:*:*

References for CVE-2016-6463

cvelogic Threat Intelligence