# CVE-2009-4881: Integer overflow in n/a

> An integer overflow in glibc's strfmon function allows attackers to cause a denial of service via crafted format strings.

- **Severity:** Medium 5.0 (`AV:N/AC:L/Au:N/C:N/I:N/A:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 1 Jun 2010
- **Updated:** 7 Aug 2024
- **Also known as:** DEBIAN-CVE-2009-4881, GHSA-q4g7-ccjm-h2xx

## What is CVE-2009-4881?

CVE-2009-4881 is a medium-severity vulnerability in Gnu Glibc, published on 1 Jun 2010. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Integer overflow in the __vstrfmon_l function in stdlib/strfmon_l.c in the strfmon implementation in the GNU C Library (aka glibc or libc6) before 2.10.1 allows context-dependent attackers to cause a denial of service (application crash) via a crafted format string, as demonstrated by the %99999999999999999999n string, a related issue to CVE-2008-1391.

Weakness: CWE-189

## Which versions are affected by CVE-2009-4881?

It affects 1 product.


Products: Gnu Glibc.

## How do I fix CVE-2009-4881?

Upgrade to a fixed version.

## Is CVE-2009-4881 being exploited?

There is no known exploitation of CVE-2009-4881 in the wild and no public exploit code.

## Other vulnerabilities in Gnu Glibc

- [CVE-2026-5450](https://insights.sbomify.com/CVE-2026-5450/): scanf %mc off-by-one heap buffer overflow (critical 9.8)
- [CVE-2023-25139](https://insights.sbomify.com/CVE-2023-25139/): Memory corruption in n/a (critical 9.8)
- [CVE-1999-0199](https://insights.sbomify.com/CVE-1999-0199/): Other in n/a (critical 9.8)
- [CVE-2019-1010022](https://insights.sbomify.com/CVE-2019-1010022/): Security feature bypass in glibc (critical 9.8)
- [CVE-2005-3590](https://insights.sbomify.com/CVE-2005-3590/): Memory corruption in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2009-4881 and fix it if it is affected.

What it is: CVE-2009-4881 is a medium-severity vulnerability in Gnu Glibc, published on 1 Jun 2010. 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-2009-4881 in the wild and no public exploit code.

Affected product: Gnu Glibc. 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-2009-4881/ (Markdown: https://insights.sbomify.com/CVE-2009-4881/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2009-4881
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2009-4881
- OSV: https://osv.dev/vulnerability/CVE-2009-4881

---
From sbomify Insights: https://insights.sbomify.com/CVE-2009-4881/
Summaries are generated and may contain mistakes; the official description above is the record.