# CVE-2021-35937: Race condition in RPM

> A local unprivileged user can exploit a race condition in RPM to bypass security checks and gain root privileges, compromising system integrity and availability.

- **Severity:** Medium 6.4 (`CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 25 Aug 2022
- **Updated:** 4 Aug 2024
- **Also known as:** AZL-10766, CLSA-2024-1721124363, CLSA-2024-1721124939, DEBIAN-CVE-2021-35937, GHSA-63x9-9q4w-j636, UBUNTU-CVE-2021-35937

## What is CVE-2021-35937?

CVE-2021-35937 is a medium-severity vulnerability in Fedoraproject Fedora, published on 25 Aug 2022. 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 rpm. A local unprivileged user could use this flaw to bypass the checks that were introduced in response to CVE-2017-7500 and CVE-2017-7501, potentially gaining root privileges. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

Weakness: CWE-367 (Time-of-check Time-of-use (TOCTOU) Race Condition), CWE-59 (Improper Link Resolution Before File Access)

## Which versions are affected by CVE-2021-35937?

It affects 3 products.


Products: Fedoraproject Fedora, Redhat Enterprise Linux, Rpm Rpm.

## How do I fix CVE-2021-35937?

Apply the vendor's patch.

## Is CVE-2021-35937 being exploited?

There is no known exploitation of CVE-2021-35937 in the wild and no public exploit code.

## Other vulnerabilities in Fedoraproject Fedora

- [CVE-2024-4577](https://insights.sbomify.com/CVE-2024-4577/): PHP-CGI OS Command Injection (critical 9.8, exploited in the wild)
- [CVE-2021-39226](https://insights.sbomify.com/CVE-2021-39226/): Grafana Authentication Bypass (critical 9.8, exploited in the wild)
- [CVE-2019-5544](https://insights.sbomify.com/CVE-2019-5544/): VMware ESXi and Horizon DaaS OpenSLP Heap-Based Buffer Overflow (critical 9.8, exploited in the wild)
- [CVE-2024-4947](https://insights.sbomify.com/CVE-2024-4947/): Google Chromium V8 Type Confusion (critical 9.6, exploited in the wild)
- [CVE-2024-4671](https://insights.sbomify.com/CVE-2024-4671/): Google Chromium Visuals Use-After-Free (critical 9.6, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-35937 and fix it if it is affected.

What it is: CVE-2021-35937 is a medium-severity vulnerability in Fedoraproject Fedora, published on 25 Aug 2022. 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-2021-35937 in the wild and no public exploit code.

Affected product: Fedoraproject Fedora. 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-2021-35937/ (Markdown: https://insights.sbomify.com/CVE-2021-35937/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-35937
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-35937
- OSV: https://osv.dev/vulnerability/CVE-2021-35937

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-35937/
Summaries are generated and may contain mistakes; the official description above is the record.