# CVE-2013-4143: Auth bypass in n/a

> Attackers can bypass the screen lock in xlockmore by exploiting improper handling of NULL values from crypt functions, allowing unauthorized access to the locked session.

- **Severity:** Low 2.1 (`AV:L/AC:L/Au:N/C:N/I:N/A:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 30 May 2014
- **Updated:** 6 Aug 2024
- **Also known as:** GHSA-jcgx-qjj8-pgf8, MGASA-2013-0225, openSUSE-SU-2024:10134-1

## What is CVE-2013-4143?

CVE-2013-4143 is a low-severity authentication bypass vulnerability in n/a, published on 30 May 2014. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

The (1) checkPasswd and (2) checkGroupXlockPasswds functions in xlockmore before 5.43 do not properly handle when a NULL value is returned upon an error by the crypt or dispcrypt function as implemented in glibc 2.17 and later, which allows attackers to bypass the screen lock via vectors related to invalid salts.

## Which versions are affected by CVE-2013-4143?

It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `xlockmore` | openSUSE:Tumbleweed | All versions | 5.45-3.8 |

Products: David Bagley Xlockmore.

## How do I fix CVE-2013-4143?

Upgrade to a fixed version.

## Is CVE-2013-4143 being exploited?

There is no known exploitation of CVE-2013-4143 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2013-4143 and fix it if it is affected.

What it is: CVE-2013-4143 is a low-severity authentication bypass vulnerability in n/a, published on 30 May 2014. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2013-4143 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-2013-4143/ (Markdown: https://insights.sbomify.com/CVE-2013-4143/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2013-4143
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2013-4143
- OSV: https://osv.dev/vulnerability/CVE-2013-4143

---
From sbomify Insights: https://insights.sbomify.com/CVE-2013-4143/
Summaries are generated and may contain mistakes; the official description above is the record.