CVE-2023-39780: ASUS RT-AX55 Routers OS Command Injection Vulnerability

Vulnerability summary

CVE-2023-39780 is a high (CVSS 8.8) OS Command Injection vulnerability in ASUS RT-AX55 Routers. It is known to be exploited: CISA lists it, first on 02-06-2025. EPSS estimates a 39.51% chance of exploitation in the next 30 days, higher than 98.6% of scored vulnerabilities. 2 public exploits are recorded.

Timeline

1. 11-09-2023
   PublishedVulnerability first disclosed.
2. 02-06-2025
   Added to CISA KEVASUS RT-AX55 Routers OS Command Injection Vulnerability
3. 23-06-2025
   CISA remediation dueApply mitigations per vendor instructions.
4. 21-10-2025
   Last modifiedVulnerability information updated.

Description

On ASUS RT-AX55 3.0.0.4.386.51598 devices, authenticated attackers can perform OS command injection via the /start_apply.htm qos_bw_rulelist parameter. NOTE: for the similar "token-generated module" issue, see CVE-2023-41345; for the similar "token-refresh module" issue, see CVE-2023-41346; for the similar "check token module" issue, see CVE-2023-41347; and for the similar "code-authentication module" issue, see CVE-2023-41348.

• CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.