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

> Unauthenticated remote attackers can bypass configured access control lists on Cisco SD-WAN vEdge devices by exploiting improper implicit deny enforcement.

- **Severity:** Medium 5.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 24 Sep 2025
- **Updated:** 24 Sep 2025
- **Also known as:** GHSA-97xx-3c9q-f5rx

## What is CVE-2025-20339?

CVE-2025-20339 is a medium-severity vulnerability in Cisco SD-WAN vEdge Cloud, published on 24 Sep 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-284 (Improper Access Control)

## Which versions are affected by CVE-2025-20339?


## How do I fix CVE-2025-20339?

No fix has been published for CVE-2025-20339 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-20339 being exploited?

There is no known exploitation of CVE-2025-20339 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-20339 and fix it if it is affected.

What it is: CVE-2025-20339 is a medium-severity vulnerability in Cisco SD-WAN vEdge Cloud, published on 24 Sep 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-20339 in the wild and no public exploit code.

Affected product: Cisco SD-WAN vEdge Cloud. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-20339/ (Markdown: https://insights.sbomify.com/CVE-2025-20339/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-20339
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-20339
- OSV: https://osv.dev/vulnerability/CVE-2025-20339

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-20339/
Summaries are generated and may contain mistakes; the official description above is the record.