← Vulnerability feed

Vulnerability record · CVE-2023-39240 · published 7 September 2023

CVE-2023-39240: Asus rt-ax55 firmware vulnerability

Asus · Rt Ax55 Firmware

It is identified a format string vulnerability in ASUS RT-AX56U V2’s iperf client function API. This vulnerability is caused by lacking validation for a specific value within its set_iperf3_cli.cgi module. A remote attacker with administrator privilege can exploit this vulnerability to perform remote arbitrary code execution, arbitrary system operation or disrupt service.

7.2 CVSS 3.1 High EPSS 1.3% · top 30.8% CWE-134 · CWE-134
7.2CVSS 3.1 base score
1.3%EPSS exploitation probability, 30 days
NoNot in CISA KEV
3Affected product versions listed by NVD
2References
17 Jun 2026Last modified by NVD

Description

It is identified a format string vulnerability in ASUS RT-AX56U V2’s iperf client function API. This vulnerability is caused by lacking validation for a specific value within its set_iperf3_cli.cgi module. A remote attacker with administrator privilege can exploit this vulnerability to perform remote arbitrary code execution, arbitrary system operation or disrupt service.

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

Affected products

3 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://www.twcert.org.tw/tw/cp-132-7356-021bf-1.html Third Party Advisory
https://www.twcert.org.tw/tw/cp-132-7356-021bf-1.html Third Party Advisory

Track CVE-2023-39240 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

8.8CVE-2023-39780ASUS RT-AX55 Router OS Command Injection via qos_bw_rulelistASUS RT-AX55 firmware 3.0.0.4.386.51598 fails to sanitize the qos_bw_rulelist parameter on /start_apply.htm, allowing OS command injection. An attack…KEVEPSS 40%analysed9.8CVE-2023-35087Asus rt-ac86u firmware vulnerabilityIt is identified a format string vulnerability in ASUS RT-AX56U V2 & RT-AC86U. This vulnerability is caused by lacking validation for a specific valu…EPSS 1.1%9.8CVE-2022-26376Asuswrt out-of-bounds write vulnerabilityA memory corruption vulnerability exists in the httpd unescape functionality of Asuswrt prior to 3.0.0.4.386_48706 and Asuswrt-Merlin New Gen prior t…EPSS 1.4%9.8CVE-2021-41435Asus gt-ax11000 firmware improper restriction of authentication attempts vulnerabilityA brute-force protection bypass in CAPTCHA protection in ASUS ROG Rapture GT-AX11000, RT-AX3000, RT-AX55, RT-AX56U, RT-AX56U_V2, RT-AX58U, RT-AX82U, …EPSS 6.5%9.8CVE-2018-8826Asus rt-ac51u firmware improper input validation vulnerabilityASUS RT-AC51U, RT-AC58U, RT-AC66U, RT-AC1750, RT-ACRH13, and RT-N12 D1 routers with firmware before 3.0.0.4.380.8228; RT-AC52U B1, RT-AC1200 and RT-N…EPSS 4.2%9.8CVE-2018-9285Asus rt-ac66u firmware os command injection vulnerabilityMain_Analysis_Content.asp in /apply.cgi on ASUS RT-AC66U, RT-AC68U, RT-AC86U, RT-AC88U, RT-AC1900, RT-AC2900, and RT-AC3100 devices before 3.0.0.4.38…EPSS 3.6%9.0CVE-2021-43702Asus zenwifi xd4s firmware cross-site scripting vulnerabilityASUS RT-A88U 3.0.0.4.386_45898 is vulnerable to Cross Site Scripting (XSS). The ASUS router admin panel does not sanitize the WiFI logs correctly, if…EPSS 0.98%8.8CVE-2023-41346Asus rt-ax55 firmware os command injection vulnerabilityASUS RT-AX55’s authentication-related function has a vulnerability of insufficient filtering of special characters within its token-refresh module. A…EPSS 1.2%

Source: NIST National Vulnerability Database (record CVE-2023-39240), CISA KEV, FIRST EPSS (scores of 2026-10-11). This page is refreshed as NVD updates the record.