# CVE-2014-3931: Multi-Router Looking Glass (MRLG) Buffer Overflow

> Remote attackers can trigger arbitrary memory writes in MRLG, potentially leading to code execution or service crashes.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Yes, since 7 Jul 2025 (CISA KEV)
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 31 Mar 2017
- **Updated:** 21 Oct 2025
- **Also known as:** GHSA-vwmm-77c8-pxrj

## What is CVE-2014-3931?

CVE-2014-3931 is a critical memory corruption vulnerability in n/a, published on 31 Mar 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

fastping.c in MRLG (aka Multi-Router Looking Glass) before 5.5.0 allows remote attackers to cause an arbitrary memory write and memory corruption.

Weakness: CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2014-3931?

It affects 1 product.


Products: Multi-Router Looking Glass Project Multi-Router Looking Glass.

## How do I fix CVE-2014-3931?

No fix has been published for CVE-2014-3931 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 28 Jul 2025.

## Is CVE-2014-3931 being exploited?

Yes. Attackers have exploited CVE-2014-3931 in the wild since at least 7 Jul 2025.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2014-3931 and fix it if it is affected.

What it is: CVE-2014-3931 is a critical memory corruption vulnerability in n/a, published on 31 Mar 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: Yes. Attackers have exploited CVE-2014-3931 in the wild since at least 7 Jul 2025.

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-2014-3931/ (Markdown: https://insights.sbomify.com/CVE-2014-3931/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2014-3931
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2014-3931
- OSV: https://osv.dev/vulnerability/CVE-2014-3931

---
From sbomify Insights: https://insights.sbomify.com/CVE-2014-3931/
Summaries are generated and may contain mistakes; the official description above is the record.