# CVE-2021-41990: Integer overflow in n/a

> Remote attackers can cause denial of service in strongSwan via crafted RSASSA-PSS certificates triggering an integer overflow in the gmp plugin.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 18 Oct 2021
- **Updated:** 4 Aug 2024
- **Also known as:** ALPINE-CVE-2021-41990, AZL-6896, DEBIAN-CVE-2021-41990, GHSA-3wp5-cvp4-5h42, UBUNTU-CVE-2021-41990

## What is CVE-2021-41990?

CVE-2021-41990 is a high-severity vulnerability in Debian Debian Linux, published on 18 Oct 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The gmp plugin in strongSwan before 5.9.4 has a remote integer overflow via a crafted certificate with an RSASSA-PSS signature. For example, this can be triggered by an unrelated self-signed CA certificate sent by an initiator. Remote code execution cannot occur.

Weakness: CWE-190 (Integer Overflow or Wraparound)

## Which versions are affected by CVE-2021-41990?

It affects 20 products.


Products: Debian Debian Linux, Fedoraproject Fedora, Siemens 6gk5615-0aa00-2aa2 Firmware, Siemens 6gk5804-0ap00-2aa2 Firmware, Siemens 6gk5812-1aa00-2aa2 Firmware, Siemens 6gk5812-1ba00-2aa2 Firmware, Siemens 6gk5816-1aa00-2aa2 Firmware, Siemens 6gk5816-1ba00-2aa2 Firmware, Siemens 6gk5826-2ab00-2ab2 Firmware, Siemens 6gk5856-2ea00-3aa1 Firmware, Siemens 6gk5856-2ea00-3da1 Firmware, Siemens 6gk5874-2aa00-2aa2 Firmware, Siemens 6gk5874-3aa00-2aa2 Firmware, Siemens 6gk5876-3aa02-2ba2 Firmware, Siemens 6gk5876-3aa02-2ea2 Firmware, Siemens 6gk5876-4aa00-2ba2 Firmware, Siemens 6gk5876-4aa00-2da2 Firmware, Siemens 6gk6108-4am00-2ba2 Firmware, Siemens 6gk6108-4am00-2da2 Firmware, Strongswan Strongswan.

## How do I fix CVE-2021-41990?

Upgrade to a fixed version.

## Is CVE-2021-41990 being exploited?

There is no known exploitation of CVE-2021-41990 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)
- [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-2021-41990 and fix it if it is affected.

What it is: CVE-2021-41990 is a high-severity vulnerability in Debian Debian Linux, published on 18 Oct 2021. 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-2021-41990 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-2021-41990/ (Markdown: https://insights.sbomify.com/CVE-2021-41990/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-41990
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-41990
- OSV: https://osv.dev/vulnerability/CVE-2021-41990

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-41990/
Summaries are generated and may contain mistakes; the official description above is the record.