CVE-2025-20393

CISA description

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

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

Notes & references

• Please adhere to Cisco's guidelines to assess exposure and mitigate risks. Check for signs of potential compromise on all internet accessible Cisco products affected by this vulnerability. Apply any final mitigations provided by the vendor as soon as they become available. For more information please see: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sma-attack-N9bf4
• https://nvd.nist.gov/vuln/detail/CVE-2025-20393

Where this lands in 800-53

Vulnerability data triggers these controls during assessment and continuous monitoring.

• RA-5 · Vulnerability Monitoring and Scanning
• SI-2 · Flaw Remediation
• CM-6 · Configuration Settings
• SI-7 · Software, Firmware, and Information Integrity
• CM-8 · System Component Inventory

External lookups

• NVD · CVE-2025-20393
• CVE.org · CVE-2025-20393
• CISA KEV catalog (canonical)