---
title: "CVE-2025-20393: Cisco Multiple Products Improper Input Validation Vulnerability"
url: https://erroneo.us/security/cve/CVE-2025-20393/
description: "CVE-2025-20393 (Cisco Multiple Products): Exploited in the wild (CISA KEV). A vulnerability in the Spam Quarantine feature of Cisco AsyncOS Software for…"
type: vulnerability-record
section: "Security Digest"
date_published: 2025-12-17
date_modified: 2026-10-07
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2025-20393"
kev: true
cvss: 10
epss: 0.32392
license: All rights reserved. Quote with attribution and a link.
---

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

**Signal:** Exploited: patch now if you run it. CISA has confirmed exploitation in the wild. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Yes, if you run Cisco Multiple Products. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2025-12-17, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2025-12-24 ; treat that as the outer limit, not the target.
- EPSS 32.4% , percentile 98: FIRST’s model estimates a 32.4% chance of exploitation activity in the next 30 days, higher than 98% of all scored CVEs (very high). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.

## What it is

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.

## Affected products (CVE record)

- Cisco Cisco Secure Email: 14.0.0-698, 13.5.1-277, 13.0.0-392, 14.2.0-620, 13.0.5-007, 13.5.4-038, 14.2.1-020, 14.3.0-032, 15.0.0-104, 15.0.1-030, 15.5.0-048, 15.5.1-055
- Cisco Cisco Secure Email and Web Manager: 13.6.2-023, 13.6.2-078, 13.0.0-249, 13.0.0-277, 13.8.1-052, 13.8.1-068, 13.8.1-074, 14.0.0-404, 12.8.1-002, 14.1.0-227, 13.6.1-201, 14.2.0-203

## Severity

- cisco CVSS 3.1: 10 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H`

## Exploitation

- CISA KEV: added 2025-12-17; federal due date 2025-12-24. Known ransomware use: Unknown.
- CISA 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.
- CISA SSVC assessment: exploitation active , automatable yes , technical impact total .
- FIRST EPSS (model of 2026-10-21): 32.39% probability of exploitation activity in the next 30 days; percentile 98.

## Sources

- [Listed in CISA KEV notes (sec.cloudapps.cisco.com)](https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sma-attack-N9bf4)
- [CVE.org record CVE-2025-20393](https://www.cve.org/CVERecord?id=CVE-2025-20393)
- [NVD entry CVE-2025-20393](https://nvd.nist.gov/vuln/detail/CVE-2025-20393)
- [CISA Known Exploited Vulnerabilities catalog entry](https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-20393)

---
Source page: https://erroneo.us/security/cve/CVE-2025-20393/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt