# CVE-2021-20197: Race condition in binutils

> An unprivileged user can exploit a race condition in binutils utilities to overwrite arbitrary files and escalate privileges when run by a privileged user.

- **Severity:** Medium 6.3 (`CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N`)
- **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 Mar 2021
- **Updated:** 3 Dec 2025
- **Also known as:** AZL-41714, DEBIAN-CVE-2021-20197, GHSA-rq67-5wpf-96wv, OESA-2021-1153, UBUNTU-CVE-2021-20197

## What is CVE-2021-20197?

CVE-2021-20197 is a medium-severity vulnerability in Gnu Binutils, published on 26 Mar 2021. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

There is an open race window when writing output in the following utilities in GNU binutils version 2.35 and earlier:ar, objcopy, strip, ranlib. When these utilities are run as a privileged user (presumably as part of a script updating binaries across different users), an unprivileged user can trick these utilities into getting ownership of arbitrary files through a symlink.

Weakness: CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization), CWE-59 (Improper Link Resolution Before File Access)

## Which versions are affected by CVE-2021-20197?

It affects 6 products.


Products: Broadcom Brocade Fabric Operating System Firmware, Gnu Binutils, Netapp Cloud Backup, Netapp Ontap Select Deploy Administration Utility, Netapp Solidfire \& Hci Management Node, Redhat Enterprise Linux.

## How do I fix CVE-2021-20197?

Apply the vendor's patch.

## Is CVE-2021-20197 being exploited?

There is no known exploitation of CVE-2021-20197 in the wild and no public exploit code.

## Other vulnerabilities in Gnu Binutils

- [CVE-2023-27534](https://insights.sbomify.com/CVE-2023-27534/): Path traversal in https://github.com/curl/curl (high 8.8)
- [CVE-2021-4197](https://insights.sbomify.com/CVE-2021-4197/): Privilege escalation in kernel (high 7.8)
- [CVE-2023-27538](https://insights.sbomify.com/CVE-2023-27538/): Auth bypass in https://github.com/curl/curl (high 7.7)
- [CVE-2021-27218](https://insights.sbomify.com/CVE-2021-27218/): Integer overflow in n/a (high 7.5)
- [CVE-2021-27219](https://insights.sbomify.com/CVE-2021-27219/): Integer overflow in n/a (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-20197 and fix it if it is affected.

What it is: CVE-2021-20197 is a medium-severity vulnerability in Gnu Binutils, published on 26 Mar 2021. 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-2021-20197 in the wild and no public exploit code.

Affected product: Gnu Binutils. 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-2021-20197/ (Markdown: https://insights.sbomify.com/CVE-2021-20197/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-20197
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-20197
- OSV: https://osv.dev/vulnerability/CVE-2021-20197

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-20197/
Summaries are generated and may contain mistakes; the official description above is the record.