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

Q: How do I fix CVE-2014-3931?

multi-router looking glass: upgrade to newer than 5.4.1. Exact commands for each OS are on this page.

Q: Is CVE-2014-3931 being exploited?

Yes. CVE-2014-3931 is on the CISA Known Exploited Vulnerabilities list, so treat it as patch-now.

Q: What does CVE-2014-3931 affect?

CVE-2014-3931 affects multi-router looking glass. Severity is critical (CVSS 9.8). 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.

Q: How urgent is CVE-2014-3931?

Priority 97/100. Critical severity; EPSS top 2%: very likely to be exploited; Exploited in the wild (CISA KEV); Public exploit reference; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action

Patch now

CRITICAL 9.8EXPLOITEDREMOTEUPGRADE

CVE-2014-3931 is a critical-severity flaw (CVSS 9.8) affecting multi-router looking glass, reported as exploited in the wild. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

Critical severity
EPSS top 2%: very likely to be exploited
Exploited in the wild (CISA KEV)
Public exploit reference
CISA SSVC: automatable with total technical impact
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	29.0% (top 2%)
CISA exploited list	Yes, fix due 2025-07-28
Weakness	CWE-119
Published	2017-03-31
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: multi-router looking glass project

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2017-03-31 16:59 UTCPublished CVE record published
2025-07-07Exploited Added to the CISA Known Exploited Vulnerabilities list
2025-07-28Deadline CISA due date for US federal agencies to patch
2026-06-17 00:09 UTCUpdated Record last modified

multi-router looking glass project multi-router looking glass UPGRADE

Affected: <= 5.4.1

Fixed in: newer than 5.4.1

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy multi-router-looking-glass || rpm -q multi-router-looking-glass || multi-router-looking-glass --version

2. UPGRADE to newer than 5.4.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade multi-router-looking-glass

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade multi-router-looking-glass

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Exact fixes by distribution

Fedora 46 · root · FIXED · 6.40.04-7.fc46 · FEDORA-2026-7329868400 · source

sudo dnf upgrade --advisory=FEDORA-2026-7329868400

Verify at the official source NVD · CVE Program · CISA KEV catalog · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2014-3931?

multi-router looking glass: upgrade to newer than 5.4.1. Exact commands for each OS are on this page.

Is CVE-2014-3931 being exploited?

Yes. CVE-2014-3931 is on the CISA Known Exploited Vulnerabilities list, so treat it as patch-now.

What does CVE-2014-3931 affect?

CVE-2014-3931 affects multi-router looking glass. Severity is critical (CVSS 9.8). 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.

How urgent is CVE-2014-3931?

Priority 97/100. Critical severity; EPSS top 2%: very likely to be exploited; Exploited in the wild (CISA KEV); Public exploit reference; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action

References

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