# CVE-2020-25653: Race condition in spice-vdagent

> A race condition in spice-vdagentd allows local users to cause denial of service or leak host information by becoming the active agent.

- **Severity:** Medium 6.3 (`CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 26 Nov 2020
- **Updated:** 4 Aug 2024
- **Also known as:** AZL-7365, DEBIAN-CVE-2020-25653, GHSA-5v7v-8wfp-pqqp, UBUNTU-CVE-2020-25653

## What is CVE-2020-25653?

CVE-2020-25653 is a medium-severity vulnerability in Debian Debian Linux, published on 26 Nov 2020. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A race condition vulnerability was found in the way the spice-vdagentd daemon handled new client connections. This flaw may allow an unprivileged local guest user to become the active agent for spice-vdagentd, possibly resulting in a denial of service or information leakage from the host. The highest threat from this vulnerability is to data confidentiality as well as system availability. This flaw affects spice-vdagent versions 0.20 and prior.

Weakness: CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization)

## Which versions are affected by CVE-2020-25653?

It affects 3 products.


Products: Debian Debian Linux, Fedoraproject Fedora, Spice-Space Spice-Vdagent.

## How do I fix CVE-2020-25653?

Upgrade to a fixed version.

## Is CVE-2020-25653 being exploited?

There is no known exploitation of CVE-2020-25653 in the wild and no public exploit code.

## Other vulnerabilities in Debian Debian Linux

- [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild)
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- [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild)
- [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild)
- [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-25653 and fix it if it is affected.

What it is: CVE-2020-25653 is a medium-severity vulnerability in Debian Debian Linux, published on 26 Nov 2020. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2020-25653 in the wild and no public exploit code.

Affected product: Debian Debian Linux. 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-2020-25653/ (Markdown: https://insights.sbomify.com/CVE-2020-25653/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-25653
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-25653
- OSV: https://osv.dev/vulnerability/CVE-2020-25653

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-25653/
Summaries are generated and may contain mistakes; the official description above is the record.