# CVE-2021-45960: Integer overflow in n/a

> An integer overflow in libexpat's storeAtts function can cause memory corruption, potentially leading to denial of service or arbitrary code execution.

- **Severity:** High 8.8 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 1 Jan 2022
- **Updated:** 14 Oct 2026
- **Also known as:** ALPINE-CVE-2021-45960, AZL-7124, CLEANSTART-2026-CC51357, DEBIAN-CVE-2021-45960, GHSA-pfmv-2r4f-j9mj, JLSEC-2025-42, UBUNTU-CVE-2021-45960

## What is CVE-2021-45960?

CVE-2021-45960 is a high-severity vulnerability in Debian Debian Linux, published on 1 Jan 2022. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

In Expat (aka libexpat) before 2.4.3, a left shift by 29 (or more) places in the storeAtts function in xmlparse.c can lead to realloc misbehavior (e.g., allocating too few bytes, or only freeing memory).

Weakness: CWE-682 (Incorrect Calculation)

## Which versions are affected by CVE-2021-45960?

It affects 8 products.


Products: Debian Debian Linux, Libexpat Project Libexpat, Netapp Active Iq Unified Manager, Netapp Hci Baseboard Management Controller, Netapp Oncommand Workflow Automation, Netapp Solidfire \& Hci Management Node, Siemens Sinema Remote Connect Server, Tenable Nessus.

## How do I fix CVE-2021-45960?

Upgrade to a fixed version.

## Is CVE-2021-45960 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-45960 exists.

Public exploit code:

- https://github.com/nanopathi/external_expat_AOSP10_r33_CVE-2021-45960 (github_poc): https://github.com/nanopathi/external_expat_AOSP10_r33_CVE-2021-45960
- https://github.com/Trinadh465/external_lib_AOSP10_r33_CVE-2021-45960_CVE-2021-46143- (github_poc): https://github.com/Trinadh465/external_lib_AOSP10_r33_CVE-2021-45960_CVE-2021-46143-

## 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)
- [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild)
- [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-2021-45960 and fix it if it is affected.

What it is: CVE-2021-45960 is a high-severity vulnerability in Debian Debian Linux, published on 1 Jan 2022. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-45960 exists.

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-2021-45960/ (Markdown: https://insights.sbomify.com/CVE-2021-45960/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-45960
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-45960
- OSV: https://osv.dev/vulnerability/CVE-2021-45960

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-45960/
Summaries are generated and may contain mistakes; the official description above is the record.