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
Affects ASUS RT-AX55 routers with NVRAM qos_enable set to 1 and qos_type set to 2. The checked facts give no vendor rating and no fixed version.
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Listed in CISA KEV
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Actively exploited
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
The firmware on ASUS RT-AX55 routers is affected, specifically the web management interface's /start_apply.htm handler. An attacker with valid login credentials could inject operating system commands through the qos_bw_rulelist parameter, potentially gaining control of the device.
Summarized by anthropic/claude-haiku-5.5. Verify details against the original sources.
Read the original 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.
Timeline
- CVE published
- Added to CISA KEV
CISA has evidence of exploitation in the wild
- CISA remediation deadline
Due date for US federal agencies to patch
- Record last updated
- EPSS reached 10%
FIRST estimates at least a 10% chance of exploitation in the next 30 days
Affected versions
- ASUS RT-AX55
3.0.0.4.386.51598
References 6
Questions about CVE-2023-39780
What does this mean?
An authenticated user can inject operating system commands through the qos_bw_rulelist value sent to /start_apply.htm, and the router then runs those commands on the device.Source: github.com
Am I affected, and how do I check?
The facts name RT-AX55 firmware 3.0.0.4.386.51598 and only when NVRAM qos_enable is 1 and qos_type is 2. To check a setup, look at the router's QoS settings or the NVRAM values for qos_enable and qos_type.Source: github.com
What should I do about it?
The checked facts do not name a fixed version or upgrade target, so no upgrade step can be given from them.Source: github.com
Is it being exploited?
Yes. CISA added it to its Known Exploited Vulnerabilities catalog on 2025-06-02, which means it has evidence of attacks. No public exploit code is tracked.Source: cisa.gov, cve.now feed data
What if there's no patch?
The checked facts give no vendor workaround. The flaw needs qos_enable set to 1 with qos_type 2, so turning QoS off would remove that condition, but the facts do not confirm this as an official fix.Source: github.com