CVE-2025-20393
Cisco — Cisco Multiple Products Improper Input Validation Vulnerability
Cisco · CWE-20 — Improper input validation · in CISA KEV since 2025-12-17
EVRS 75 of 100 Urgent
Patch This Cycle
Rank 812 of 2,960 tracked
Raised to the floor for a confirmed exploited vulnerability.
Why it scores 75
Evidence available: 6 of 7 signalsListed in the CISA KEV catalog, and an EPSS probability of 0.324.
- CISA KEVApplied
- RansomwareDid not apply
- Vendor exploitationDid not apply
- EPSSApplied
- Microsoft Exploitability IndexNot applicable
- Pre-patch disclosureNo data
- KEV recencyDid not apply
- CVSSApplied
The band answers “how soon”, not “how bad”. No data for: Pre-patch disclosure. Why some signals show no data
Fix
Patch or fixed version identifiedCISA required action
- 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
- nvd.nist.gov/…/CVE-2025-20393
Fixed in
asyncos: update to 15.0.5-016 or later | asyncos: update to 15.5.4-012 or later | asyncos: update to 16.0.4-016 or later | asyncos: update to 15.0.2-007 or later | asyncos: update to 15.5.4-007 or later | asyncos: update to 16.0.4-010 or later
Affected versions
- secure email gateway virtual appliance c100v
- secure email gateway virtual appliance c300v
- secure email gateway virtual appliance c600v
- secure email and web manager virtual appliance m100v
- secure email and web manager virtual appliance m300v
- secure email and web manager virtual appliance m600v
- asyncos
< 15.0.5-016>= 15.5 < 15.5.4-012>= 16.0 < 16.0.4-016< 15.0.2-007>= 15.5 < 15.5.4-007>= 16.0 < 16.0.4-010 - secure email gateway c195
+13 more affected products; see the full list at NVD.
Remediation
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Fixed versions from NVD.
Evidence
Each value with its source| Measure | Value | Source |
|---|---|---|
| CVSS base scoreHow severe the flaw is in itself. It does not say how likely an attack is. | 10.0 | NVD |
| FIRST EPSSFIRST's estimate of the chance this is exploited in the next 30 days, and how that ranks against all CVEs. | 0.324 (98.3rd pctl) | FIRST EPSS |
| Actively exploitedWhether a source of record has confirmed attacks using it in the wild. | Confirmed | CISA KEV |
| Ransomware campaign useWhether CISA has seen ransomware operators use it. | Unknown or none | CISA KEV |
| CISA remediation deadlineThe date US federal agencies must have fixed or mitigated it. | 2025-12-24 · CISA federal deadline · Overdue by 10 months | CISA KEV |
| Public exploit moduleA module existing is not the same as active exploitation. | None known | Metasploit |
| EUVD cross-referenceENISA's record: CVSS 10.0 (v3.1), assigned by cisco. | Listed | ENISA EUVD |
Description
NVDA 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.
What CISA says to do
- 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
- nvd.nist.gov/…/CVE-2025-20393