What is CVE-2014-3931?

CVE-2014-3931 is a critical-severity vulnerability in Multi-Router Looking Glass Project, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 9.8/10. Published 2017-03-31.

How severe is CVE-2014-3931?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Is CVE-2014-3931 known to be exploited?

Yes. CVE-2014-3931 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2025-07-07), indicating it is being actively exploited. 3 public proof-of-concept repositories are indexed.

Buffer overflow in Multi-Router Looking Glass Project

CVE-2014-3931

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.

Vulnerability class: Buffer Overflow

Published 2017-03-31 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.290 (98.1th percentile), scored 2026-10-19.

Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 98th percentile — 98.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.290 · newest: 0.290 · change: 0.000

Affected products

Multi-Router Looking Glass Project

Weakness classification (CWE)

CWE-119 — Improper Restriction of Operations within the Bounds of a Memory Buffer

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on 2025-07-07. CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.

BOD 22-01 due date: 2025-07-28.

Required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Public proof-of-concept exploits

References

mrlg.op-sec.us/ (Third Party Advisory)
www.s3.eurecom.fr/cve/CVE-2014-3931.txt (Third Party Advisory)
hackerone.com/reports/16330 (Exploit, Third Party Advisory)
134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)

Frequently asked questions

What is CVE-2014-3931?: CVE-2014-3931 is a critical-severity vulnerability in Multi-Router Looking Glass Project, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 9.8/10. Published 2017-03-31.
How severe is CVE-2014-3931?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2014-3931 known to be exploited?: Yes. CVE-2014-3931 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2025-07-07), indicating it is being actively exploited. 3 public proof-of-concept repositories are indexed.