CVE-2024-40891
RCE in Zyxel Vmg1312-B10A Firmware
Raw vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HSummary
CVE-2024-40891 is a high-severity OS Command Injection (CWE-78) vulnerability in Zyxel Sbg3500-N000 Firmware. Its CVSS base score is 8.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Command and Scripting Interpreter (T1059); ranked in the top 3% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2024-40891 is a post-authentication command injection vulnerability, tracked under CWE-78, that affects the management command interface of the legacy Zyxel VMG4325-B10A DSL CPE running firmware version 1.00(AAFR.4)C0_20170615. The flaw permits an authenticated user to inject and execute arbitrary operating system commands on the device over Telnet. It carries a CVSS 3.1 score of 8.8 and is explicitly labeled unsupported when assigned.
An attacker who has already obtained valid credentials can connect via Telnet and leverage the management commands to run OS-level instructions, resulting in full compromise of the confidentiality, integrity, and availability of the affected CPE.
The Zyxel security advisory published on 4 February 2025 addresses command injection issues in certain legacy DSL CPE models, while CISA has added the CVE to its Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild.
The vulnerability's EPSS score currently stands at 0.5324 with a recorded peak of 0.5630, reflecting sustained exploitation interest against this unsupported device.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2024-38851
Vulnerability Data
**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.
- CWE(s)
- KEV Date Added
- 11 February 2025
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V1.2.5V1.2.8V15.2.5
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation can discover missing or incorrect command sanitization during development.
Input validation directly neutralizes or rejects special characters that would otherwise alter OS command structure.
Least privilege reduces the permissions available to any process that could be subverted by injected commands.
Least functionality restricts available OS commands and interpreters, limiting the blast radius of injection.
Secure engineering principles require proper neutralization of untrusted input before command construction.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
PR.PS-06's SDLC practices directly require secure coding and input handling that blocks command-injection defects, yet the single broad outcome leaves many specific neutralization vectors and verification gaps unaddressed.
Routine patching/maintenance can remediate known command-injection CVEs in dependencies (partial forward) but does nothing to stop developers from introducing improper neutralization in custom code (none reverse).
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing and code review target insecure use of operating-system command interfaces, catching command-injection flaws introduced during development.