CVE-2014-3931

MRLG (Multi-Router Looking Glass) Multi-Router Looking Glass (MRLG) · Switches, routers and SD-WAN

Multi-Router Looking Glass (MRLG) Buffer Overflow Vulnerability

At a glance

Exploited. Added to CISA’s catalog of exploited vulnerabilities on July 7, 2025.

Affected product: MRLG (Multi-Router Looking Glass) Multi-Router Looking Glass (MRLG) (category Switches, routers and SD-WAN, indicative classification). Name in CISA’s catalog: Looking Glass Multi-Router Looking Glass (MRLG).

What should I do?

Apply the patches or mitigations from MRLG (Multi-Router Looking Glass); if none are available, stop using the product. For cloud services, follow the guidance from MRLG (Multi-Router Looking Glass).

Deadline set by CISA for US federal agencies: 21 days (due July 28, 2025). It only binds those agencies, but it is a useful measure of urgency.

The vendor’s specific advisory is listed in the NVD references: CVE-2014-3931 on the NVD website.

Original text of the required action (CISA)

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

Timeline

March 31, 2017 Vulnerability published Publication date (NVD)
July 7, 2025 Exploitation confirmed Added to CISA’s KEV catalog
July 28, 2025 CISA deadline Remediation deadline set for US federal agencies

The facts, with their sources

Exploitation confirmed: Yes, on July 7, 2025 Date added to the catalog of exploited vulnerabilities. Exploitation itself may have started earlier. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
Ransomware: No known use to date That does not guarantee it is not being used: the information is not public. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
Hunt for compromise: Not requested by CISA Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
CISA required action: Apply the patches or mitigations from MRLG (Multi-Router Looking Glass); if none are available, stop using the product. For cloud services, follow the guidance from MRLG (Multi-Router Looking Glass). Rewritten by this site from CISA’s original text. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
CISA deadline: July 28, 2025, 21 days Set for US federal agencies: a measure of urgency, not an obligation elsewhere. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
Vulnerability published: March 31, 2017 Source: National Vulnerability Database (NVD), collected September 29, 2026 at 15:00 UTC
Product according to CISA: Looking Glass Multi-Router Looking Glass (MRLG) Filed by this site under “Switches, routers and SD-WAN” (indicative classification). Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Technical detail of the score: attack vector, complexity, impact. Source: National Vulnerability Database (NVD), collected September 29, 2026 at 15:00 UTC

Severity and activity

9.8 / 10 CVSS severity: critical

Score from the NVD. Collected Sep 29, 2026.

— Probability of exploitation in the next 30 days (EPSS)

FIRST’s EPSS model. Since exploitation is already confirmed, this figure is mostly useful to compare activity. Collected Sep 29, 2026.

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.

Multi-Router Looking Glass (MRLG) contains a buffer overflow vulnerability that could allow remote attackers to cause an arbitrary memory write and memory corruption.

Summary from CISA (KEV catalog).

CERT-FR advisories

No advisory among the latest CERT-FR publications this site follows. That does not mean there are none.

Information reused under the Open Licence 2.0 (Etalab); the date of last update is shown for each advisory. This site is neither affiliated with nor endorsed by ANSSI.

Sources for this page

CISA KEV catalog: exploitation, date added, required action, deadline, ransomware.
NVD (NIST): CVSS severity, publication date, description, vendor references.
EPSS (FIRST): probability of exploitation.
CERT-FR: advisories and alerts (in French).
Brand and category: indicative classification by this site (method).