Exploited

CVE-2024-40891

Zyxel Home gateways and routers (DSL, CPE) · Home and small-office routers, cameras and IoT

Zyxel DSL CPE OS Command Injection Vulnerability

At a glance

Exploited. Added to CISA’s catalog of exploited vulnerabilities on February 11, 2025.

Affected product: Zyxel Home gateways and routers (DSL, CPE) (category Home and small-office routers, cameras and IoT, indicative classification). Name in CISA’s catalog: Zyxel DSL CPE Devices.

What should I do?

Apply the patches or mitigations from Zyxel; if none are available, stop using the product.

Deadline set by CISA for US federal agencies: 21 days (due March 4, 2025). It only binds those agencies, but it is a useful measure of urgency.

Zyxel security advisories page (general page, not the advisory for this vulnerability)
The vendor’s specific advisory is listed in the NVD references: CVE-2024-40891 on the NVD website.

Original text of the required action (CISA)

The impacted product could be end-of-life (EoL) and/or end-of-service (EoS). Users should discontinue product utilization if a current mitigation is unavailable.

Timeline

February 4, 2025 Vulnerability published Publication date (NVD)
February 11, 2025 Exploitation confirmed Added to CISA’s KEV catalog
March 4, 2025 CISA deadline Remediation deadline set for US federal agencies

The facts, with their sources

Exploitation confirmed: Yes, on February 11, 2025 Date added to the catalog of exploited vulnerabilities. Exploitation itself may have started earlier. Source: KEV catalog, collected September 29, 2026 at 11:25 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 11:25 UTC
Hunt for compromise: Not requested by CISA Source: KEV catalog, collected September 29, 2026 at 11:25 UTC
CISA required action: Apply the patches or mitigations from Zyxel; if none are available, stop using the product. Rewritten by this site from CISA’s original text. Source: KEV catalog, collected September 29, 2026 at 11:25 UTC
CISA deadline: March 4, 2025, 21 days Set for US federal agencies: a measure of urgency, not an obligation elsewhere. Source: KEV catalog, collected September 29, 2026 at 11:25 UTC
Vulnerability published: February 4, 2025 Source: National Vulnerability Database (NVD), collected September 29, 2026 at 11:29 UTC
Product according to CISA: Zyxel DSL CPE Devices Filed by this site under “Home and small-office routers, cameras and IoT” (indicative classification). Source: KEV catalog, collected September 29, 2026 at 11:25 UTC
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/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 11:29 UTC

Severity and activity

8.8 / 10 CVSS severity: high

Score from the vendor or CISA, relayed by 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

**UNSUPPORTED WHEN ASSIGNED** A post-authentication command injection vulnerability in the management commands of the legacy DSL CPE Zyxel VMG4325-B10A firmware version 1.00(AAFR.4)C0_20170615 could allow an authenticated attacker to execute operating system (OS) commands on an affected device via Telnet.

Multiple Zyxel DSL CPE devices contain a post-authentication command injection vulnerability in the management commands that could allow an authenticated attacker to execute OS commands via Telnet.

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).