CVE-2023-39780: ASUS RT-AX55 Routers exploited

Advisory generated from the CVE record, CISA, Exploit Observer and VEDAS: what it is, whether it is exploited, who is affected, and how to fix and detect it.

What it is

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.

Description quoted from the CVE record (assigned by mitre, published 2023-09-11).

Weakness: CWE-78 Improper Neutralization of Special Elements used in an OS Command (‘OS Command Injection’)

How it can be exploited

Exploitable over the network with low attack complexity needing low privileges and no user interaction. Impact: confidentiality high, integrity high, availability high. CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CISA assessment (SSVC): CISA assesses exploitation as active. Automatable: no. Technical impact: total.

On CISA KEV since: 2025-06-02
US federal deadline: 2025-06-23
Ransomware use: Not known

Public exploit evidence (Exploit Observer)

Also known as: BDU:2023-05508, CNNVD-202309-740, CNVD-2023-70089, EUVD-2023-43480, GHSA-6m5p-5ccp-c8p3

VEDAS cluster: VEDAS:FIZZFIRE

Exploit Observer links 6 pieces of public exploit code or detection modules that name this CVE or one of its aliases.

Exploit code and modules (6)

Code that names this CVE. A repository can be a working exploit, a scanner, a fake or malware; read it before running anything.

Code repository: https://github.com/krevetkqqq/cve-2023-39780
Code repository: https://raw.githubusercontent.com/ARPSyndicate/vedas-signatures/main/nuclei/2023/CVE-2023-39780.yaml
Code repository: https://raw.githubusercontent.com/ARPSyndicate/vedas-signatures/main/nuclei/2023/CVE-2023-39780.yaml
Code repository: https://raw.githubusercontent.com/ARPSyndicate/vedas-signatures/main/suricata/2023/CVE-2023-39780.rules
Code repository: https://raw.githubusercontent.com/ARPSyndicate/vedas-signatures/main/suricata/2023/CVE-2023-39780.rules
Code repository: https://raw.githubusercontent.com/ARPSyndicate/vedas-signatures/main/suricata/2023/CVE-2023-39780.rules

Vulnerability databases and vendor advisories (6)

Catalogue entries, not exploit evidence.

Vulnerability database or vendor advisory: https://euvd.enisa.europa.eu/enisa/EUVD-2023-43480
Vulnerability database or vendor advisory: https://github.com/advisories/GHSA-6m5p-5ccp-c8p3
Vulnerability database or vendor advisory: https://nvd.nist.gov/vuln/detail/CVE-2023-39780
Vulnerability database or vendor advisory: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-39780
Vulnerability database or vendor advisory: https://www.cnnvd.org.cn/home/globalSearch?keyword=CNNVD-202309-740
Vulnerability database or vendor advisory: https://www.cnvd.org.cn/flaw/show/CNVD-2023-70089

18 more references returned by Exploit Observer did not name this CVE or an alias, so they are left out.

VEDAS data as of 2026-11-01T17:12 UTC; fetched 2026-11-02.

Live scores

EPSS: 0.395
likely to be attacked soon
VEDAS: 0.979
strong exploit evidence
On CISA KEV: Yes, since 2025-06-02
Detection rule: Nuclei · Suricata

EPSS (chance of attack)

VEDAS (exploit evidence)

Thin horizontal line: the “likely” (EPSS 0.10) or “strong” (VEDAS 0.90) threshold. Shaded “no data” areas are periods when cve-scores did not publish. The vertical line is the day CISA added it to its exploited list.

Who is affected

Product	Affected	Not affected
ASUS RT-AX55	version 3.0.0.4.386.51598	Not stated

Version ranges exactly as the CVE record states them. “Before X” means X is the first fixed version.

Exploit Observer also maps it to: asus rt-ax55, asus rt-ax55_firmware, asustek_computer_inc. rt-ax55.

How to fix it

CISA required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Vendor guidance:

How to detect it

Nuclei template (active check)

ASUS RT-AX55 - Command Injection
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.

Name and description quoted from the template, written by VEDAS.

The template sends 1 request (GET /index.php?x=%60echo%20mut9yz22dnvb%60); it decides using status, word matchers. Severity in the template: high. Marked as not yet verified against a live vulnerable target.

Run it against a host you own or are authorised to test:

bash

nuclei -u https://your-host -t CVE-2023-39780.yaml

Show the template (36 lines)

yaml

id: CVE-2023-39780

info:
  name: "ASUS RT-AX55 - Command Injection"
  author: vedas-arpsyndicate
  severity: high
  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.
  reference:
    - https://www.exploit.observer/?keyword=CVE-2023-39780&match=exact
    - https://subdomain.center/?engine=ammonites&keyword=asus&match=exact
  classification:
    cvss-score: 8.8
    cve-id: CVE-2023-39780
    cwe-id: CWE-77
  metadata:
    verified: false
    max-request: 1
  tags: cve,cve2023,asus,cmd

http:
  - method: GET
    path:
      - "{{BaseURL}}/index.php?x=%60echo%20mut9yz22dnvb%60"
    matchers-condition: and
    matchers:
      - type: word
        part: body
        words:
          - "mut9yz22dnvb"
      - type: status
        status:
          - 200

CVE-2023-39780.yaml on GitHub

Suricata rules (network detection)

1 rule that alert on traffic matching this exploit: VEDAS CVE-2023-39780 ASUS RT-AX55 - Command Injection. Add them to your Suricata rule set and reload.

Show the rules

suricata

alert http $EXTERNAL_NET any -> $HTTP_SERVERS $HTTP_PORTS (msg:"VEDAS CVE-2023-39780 ASUS RT-AX55 - Command Injection"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"index.php"; nocase; fast_pattern; content:"mut9yz22dnvb"; nocase; classtype:web-application-attack; reference:cve,CVE-2023-39780; reference:url,https://www.exploit.observer/?keyword=CVE-2023-39780&match=exact; reference:url,https://subdomain.center/?engine=ammonites&keyword=asus&match=exact; sid:1004337; rev:2;)

CVE-2023-39780.rules on GitHub

References

Government sources

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-39780 (government-resource)

Other references

Other databases

Where this comes from

This advisory is generated automatically by VEDAS from: CVE.org record, CISA KEV, cve-scores (EPSS and VEDAS), Exploit Observer, vedas-signatures. Text in quotes is reproduced from the source; everything else is a fixed template filled with source fields. Nothing here is written by a language model. Check the vendor advisory before acting, and read how VEDAS and Exploit Observer work, and their limits.