Cisco Email Security Appliance Content Filter Bypass Vulnerability
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · High · None
- Fix status
- No fix listed
Attack profile from CVSS 3.0 · NVD. Fix status from CNA.
Summary
A vulnerability in the attachment scanning of Cisco AsyncOS Software for Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to bypass configured content filters on the device. The vulnerability is due to improper input validation of the email body. An attacker could exploit this vulnerability by naming a malicious attachment with a specific pattern. A successful exploit could allow the attacker to bypass configured content filters that would normally block the attachment.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2019-1921
- 2026-10-03 Alias added: GHSA-q86h-wvjc-7wh4
References
More Cisco Email Security Appliance vulnerabilities
- TI-2022-05357 Cisco Email Security Appliance and Cisco Secure Email and Web Manager External Authentication Bypass Vulnerability CVSS 3.1CRITICAL 9.8
- TI-2019-01567 Cisco Email Security Appliance Denial of Service Vulnerability CVSS 3.1HIGH 8.6
- TI-2018-00378 Improper input validation in Cisco Email Security Appliance CVSS 3.0HIGH 7.5
- TI-2020-02695 Cisco Email Security Appliance Content Filter Bypass Vulnerability CVSS 3.1HIGH 7.5
- TI-2019-01553 Cisco Email Security Appliance Content Filter Bypass Vulnerability CVSS 3.0HIGH 7.4
- TI-2020-03092 Cisco Email Security Appliance Denial Of Service Vulnerability CVSS 3.1HIGH 7.5
Sources
- CVE-2019-1921 · CVE Program
- CVE-2019-1921 · NVD
- FIRST EPSS
- GHSA-q86h-wvjc-7wh4 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences