CVE-2025-20393: Cisco Multiple Products Improper Input Validation Vulnerability

CISA Known Exploited Vulnerabilities

Name

Cisco Multiple Products Improper Input Validation Vulnerability

Vendor

Cisco

Product

Multiple Products

Added to the catalog

2025-12-17

Due date for US federal agencies

2025-12-24

Weaknesses

CWE-20

Catalog version

2026.10.30

Cisco Secure Email Gateway, Secure Email, AsyncOS Software, and Web Manager appliances contains an improper input validation vulnerability that allows threat actors to execute arbitrary commands with root privileges on the underlying operating system of an affected appliance.

Required action (CISA)

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Ransomware use: CISA does not mark known use of this vulnerability in ransomware campaigns.

Links in CISA's notes

• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sma-attack-N9bf4
• https://nvd.nist.gov/vuln/detail/CVE-2025-20393

Read on 2026-11-02T23:39:54.475Z under licence cisa-kev-cc0@b0067899 from https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json

NVD analysis

Status

Analyzed

Published

2025-12-17T17:15:48.523

Last modified

2026-06-17T08:41:39.983

Weaknesses

CWE-20

A vulnerability in the Spam Quarantine feature of Cisco AsyncOS Software for Cisco Secure Email Gateway and Cisco Secure Email and Web Manager could allow an unauthenticated, remote attacker to execute arbitrary system commands on an affected device with root privileges.

This vulnerability is due to insufficient validation of HTTP requests by the Spam Quarantine feature. An attacker could exploit this vulnerability by sending a crafted HTTP request to the affected device. A successful exploit could allow the attacker to execute arbitrary commands on the underlying operating system with root privileges.

References

• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sma-attack-N9bf4 (Vendor Advisory)
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-20393 (US Government Resource)

This product uses the NVD API but is not endorsed or certified by the NVD.

Read on 2026-11-02T23:42:22.836Z under licence nvd-api-terms-of-use@ff2a5288 from https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2025-20393

CVE record

Title (CNA)

Cisco Secure Email Gateway and Cisco Secure Email and Web Manager Remote Command Execution Vulnerability

Assigner

cisco

State

PUBLISHED

Published

2025-12-17T16:47:13.128Z

Updated

2026-10-07T19:22:07.139Z

Problem types

Improper Input Validation

A vulnerability in the Spam Quarantine feature of Cisco AsyncOS Software for Cisco Secure Email Gateway and Cisco Secure Email and Web Manager could allow an unauthenticated, remote attacker to execute arbitrary system commands on an affected device with root privileges.

This vulnerability is due to insufficient validation of HTTP requests by the Spam Quarantine feature. An attacker could exploit this vulnerability by sending a crafted HTTP request to the affected device. A successful exploit could allow the attacker to execute arbitrary commands on the underlying operating system with root privileges.

References

• cisco-sa-sma-attack-N9bf4

Read on 2026-11-03T02:15:00.304Z under licence cve-terms-of-use@81bfa2f3 from https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2025/20xxx/CVE-2025-20393.json

Defensive techniques (MITRE D3FEND)

D3FEND maps these defensive techniques to the weakness (CWE) that NVD lists for this CVE, through the digital artifacts the weakness affects. D3FEND does not say they stop this vulnerability.

MITRE D3FEND™ knowledge graph. © 2025 The MITRE Corporation.
"The MITRE Corporation (MITRE) hereby grants you a non-exclusive, royalty-free license to use D3FEND for research, development, and commercial purposes. Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." Terms: https://d3fend.mitre.org/tou/