# CVE-2012-1109: Denial of service in mwlib

> Attackers can cause a denial of service in mwlib by exploiting a flaw in parsing #iferror magic functions.

- **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:** No
- **Published:** 12 Nov 2019
- **Updated:** 6 Aug 2024
- **Also known as:** GHSA-2mmf-r54m-7994

## What is CVE-2012-1109?

CVE-2012-1109 is a high-severity denial of service vulnerability in Python mwlib, published on 12 Nov 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

mwlib 0.13 through 0.13.4 has a denial of service vulnerability when parsing #iferror magic functions

Weakness: CWE-755 (Improper Handling of Exceptional Conditions)

## Which versions are affected by CVE-2012-1109?

It affects 1 product.


Products: Pediapress Mwlib.

## How do I fix CVE-2012-1109?

No fix has been published for CVE-2012-1109 yet. Limit exposure of the affected software until one is available.

## Is CVE-2012-1109 being exploited?

There is no known exploitation of CVE-2012-1109 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2012-1109 and fix it if it is affected.

What it is: CVE-2012-1109 is a high-severity denial of service vulnerability in Python mwlib, published on 12 Nov 2019. 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-2012-1109 in the wild and no public exploit code.

Affected product: Python mwlib. 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-2012-1109/ (Markdown: https://insights.sbomify.com/CVE-2012-1109/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2012-1109
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2012-1109
- OSV: https://osv.dev/vulnerability/CVE-2012-1109

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From sbomify Insights: https://insights.sbomify.com/CVE-2012-1109/
Summaries are generated and may contain mistakes; the official description above is the record.