# CVE-2011-1951: Denial of service in n/a

> Remote attackers can cause denial of service via memory consumption in syslog-ng when specific global flags and PCRE versions are used.

- **Severity:** Medium 4.3 (`AV:N/AC:M/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:** 11 Jul 2011
- **Updated:** 6 Aug 2024
- **Also known as:** DEBIAN-CVE-2011-1951, GHSA-7jqv-hh4c-ww3h

## What is CVE-2011-1951?

CVE-2011-1951 is a medium-severity denial of service vulnerability in n/a, published on 11 Jul 2011. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

lib/logmatcher.c in Balabit syslog-ng before 3.2.4, when the global flag is set and when using PCRE 8.12 and possibly other versions, allows remote attackers to cause a denial of service (memory consumption) via a message that does not match a regular expression.

Weakness: CWE-399

## Which versions are affected by CVE-2011-1951?

It affects 1 product.


Products: Oneidentity Syslog-Ng.

## How do I fix CVE-2011-1951?

Upgrade to a fixed version.

## Is CVE-2011-1951 being exploited?

There is no known exploitation of CVE-2011-1951 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2008-5110](https://insights.sbomify.com/CVE-2008-5110/): Other in n/a (critical 9.3)
- [CVE-2020-8019](https://insights.sbomify.com/CVE-2020-8019/): syslog-ng: Local privilege escalation from new to root in %post (high 7.7)
- [CVE-2022-38725](https://insights.sbomify.com/CVE-2022-38725/): Integer overflow in n/a (high 7.5)
- [CVE-2002-1200](https://insights.sbomify.com/CVE-2002-1200/): Memory corruption in n/a (high 7.5)
- [CVE-2011-0343](https://insights.sbomify.com/CVE-2011-0343/): Misconfiguration in n/a (medium 6.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2011-1951 and fix it if it is affected.

What it is: CVE-2011-1951 is a medium-severity denial of service vulnerability in n/a, published on 11 Jul 2011. 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-2011-1951 in the wild and no public exploit code.

Affected product: n/a. 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-2011-1951/ (Markdown: https://insights.sbomify.com/CVE-2011-1951/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2011-1951
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2011-1951
- OSV: https://osv.dev/vulnerability/CVE-2011-1951

---
From sbomify Insights: https://insights.sbomify.com/CVE-2011-1951/
Summaries are generated and may contain mistakes; the official description above is the record.