# CVE-2025-20128: ClamAV OLE2 File Format Decryption Denial of Service Vulnerability

> An unauthenticated remote attacker can cause a denial of service in ClamAV by submitting a crafted OLE2 file, triggering an integer underflow and heap buffer overflow.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 22 Jan 2025
- **Updated:** 3 Nov 2025
- **Also known as:** DEBIAN-CVE-2025-20128, GHSA-6j5q-p9xp-3cc6, MGASA-2025-0031, MINI-vw9h-p9p6-6fv6, UBUNTU-CVE-2025-20128, USN-7229-1

## What is CVE-2025-20128?

CVE-2025-20128 is a medium-severity vulnerability in Clamav Clamav, published on 22 Jan 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability in the Object Linking and Embedding 2 (OLE2) decryption routine of ClamAV could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.

This vulnerability is due to an integer underflow in a bounds check that allows for a heap buffer overflow read. An attacker could exploit this vulnerability by submitting a crafted file containing OLE2 content to be scanned by ClamAV on an affected device. A successful exploit could allow the attacker to terminate the ClamAV scanning process, resulting in a DoS condition on the affected software.
For a description of this vulnerability, see the .
Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

Weakness: CWE-122 (Heap-based Buffer Overflow)

## Which versions are affected by CVE-2025-20128?

It affects 3 products.


Products: Cisco Secure Endpoint, Cisco Secure Endpoint Private Cloud, Clamav Clamav.

## How do I fix CVE-2025-20128?

Upgrade to a fixed version.

## Is CVE-2025-20128 being exploited?

There is no known exploitation of CVE-2025-20128 in the wild and no public exploit code.

## Other vulnerabilities in Clamav Clamav

- [CVE-2023-20032](https://insights.sbomify.com/CVE-2023-20032/): Memory corruption in Cisco Secure Endpoint (critical 9.8)
- [CVE-2022-20770](https://insights.sbomify.com/CVE-2022-20770/): ClamAV CHM File Parsing Denial of Service Vulnerability Affecting Cisco Products: April 2022 (high 8.6)
- [CVE-2026-20348](https://insights.sbomify.com/CVE-2026-20348/): ClamAV XAR File Format Processing Memory Corruption Vulnerability (high 7.5)
- [CVE-2026-20213](https://insights.sbomify.com/CVE-2026-20213/): ClamAV PE File Format Processing Out-of-Bounds Memory Corruption Vulnerability (high 7.5)
- [CVE-2026-20214](https://insights.sbomify.com/CVE-2026-20214/): ClamAV FSG File Format Processing Out-of-Bounds Memory Corruption Vulnerability (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-20128 and fix it if it is affected.

What it is: CVE-2025-20128 is a medium-severity vulnerability in Clamav Clamav, published on 22 Jan 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-2025-20128 in the wild and no public exploit code.

Affected product: Clamav Clamav. 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-2025-20128/ (Markdown: https://insights.sbomify.com/CVE-2025-20128/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-20128
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-20128
- OSV: https://osv.dev/vulnerability/CVE-2025-20128

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From sbomify Insights: https://insights.sbomify.com/CVE-2025-20128/
Summaries are generated and may contain mistakes; the official description above is the record.