Zyxel Addresses Critical RCE Flaw in Multiple Router Models

Severity: High (Score: 67.6)

Sources: Linkedin, Oodaloop, Cyberpress, Bleepingcomputer, Feedly

Summary

Zyxel has issued security updates for a critical remote command execution vulnerability, tracked as CVE-2025-13942, affecting various router models. The flaw exists in the UPnP function, allowing unauthenticated attackers to execute arbitrary OS commands on unpatched devices. Affected devices include Zyxel's 4G LTE/5G NR CPE, DSL/Ethernet CPE, Fiber ONTs, and wireless extenders.

Key Entities

• Command Injection (attack_type)
• Zero-day Exploit (attack_type)
• Zyxel (company)
• Taiwan (country)
• CVE-2024-40891 (cve)
• CVE-2025-13942 (cve)
• CVE-2025-13943 (cve)
• CVE-2025-40540 (cve)
• CVE-2026-1459 (cve)
• T1059 - Command and Scripting Interpreter (mitre_attack)
• Ex3301-t0 (platform)
• UPnP (platform)
• Vmg3625-t50b (platform)
• Windows (platform)
• OS Command Injection (vulnerability)
• Serv-U Type Confusion (vulnerability)