Security Digest · Vulnerability record · Known exploited
CVE-2014-3931: Multi-Router Looking Glass (MRLG) Buffer Overflow Vulnerability
Exploited in the wild (CISA KEV). 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.
CISA KEV · added 2025-07-07 CVSS 9.8 Critical EPSS 29.0% · p98
Should you act?
Exploited: patch now if you run it
CISA has confirmed exploitation in the wild. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.
- Yes, if you run Looking Glass Multi-Router Looking Glass (MRLG). CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2025-07-07, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2025-07-28; treat that as the outer limit, not the target.
- EPSS 29.0%, percentile 98: FIRST’s model estimates a 29.0% chance of exploitation activity in the next 30 days, higher than 98% of all scored CVEs (very high). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
What it is
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.
CISA’s summary
Multi-Router Looking Glass (MRLG) contains a buffer overflow vulnerability that could allow remote attackers to cause an arbitrary memory write and memory corruption.
Weakness type: CWE-119.
Product: Looking Glass Multi-Router Looking Glass (MRLG) · Assigned by: mitre · Published: 2017-03-31
Affected and fixed versions
| Vendor | Product | Affected versions (per CVE record) |
|---|---|---|
| n/a | n/a | see vendor advisory |
Severity scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| CISA-ADP | 3.1 | 9.8 Critical | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
- Attack vector: network (remotely reachable)
- Attack complexity: low
- Privileges required: none (no login)
- User interaction: none
- Scope: unchanged
CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.
Exploitation and urgency
- CISA KEV: added 2025-07-07; federal due date 2025-07-28. Known ransomware use: Unknown.
- CISA 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.
- CISA SSVC assessment: exploitation active, automatable yes, technical impact total.
- FIRST EPSS (model of 2026-10-21): 28.98% probability of exploitation activity in the next 30 days; percentile 98.
Timeline
- — CVE record published by mitre
- — Added to CISA’s Known Exploited Vulnerabilities catalog
- — CISA remediation deadline for US federal agencies
- — CVE record last updated
Sources and references
Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.
Vendor and project advisories, patches
- Listed in CISA KEV notes (mrlg.op-sec.us) mrlg.op-sec.us
Vulnerability records
- CVE.org record CVE-2014-3931 cve.org
- NVD entry CVE-2014-3931 nvd.nist.gov
Government
Other references from the CVE record and advisory
- mrlg.op-sec.us mrlg.op-sec.us
- s3.eurecom.fr s3.eurecom.fr
- hackerone.com hackerone.com
All exploited Looking Glass vulnerabilities · Today’s Security Digest