CVE-2023-39240

Name: CVE-2023-39240
Creator: NVD / NIST
Published: 2023-09-07T08:15:07.71+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.2/10EPSS 1.16%

Last modified Jun 17, 2026

CVE-2023-39240 is a high-severity vulnerability rated 7.2/10 on the CVSS scale. 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. EPSS estimates a 1.16% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

7.2/10

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

EPSS Probability

1.16%

63.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-134

Affected Software

Vendor	Product	Versions
Asus	Rt-Ax55 Firmware	3.0.0.4.386_50460
Asus	Rt-Ax56u V2 Firmware	3.0.0.4.386_50460
Asus	Rt-Ac86u Firmware	3.0.0.4_386_51529

References

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

Timeline

Published: Sep 7, 2023
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2023-39240?

How severe is CVE-2023-39240?

CVE-2023-39240 has a CVSS score of 7.2/10 (HIGH severity). The EPSS model estimates a 1.16% probability of exploitation in the next 30 days.

How do I fix CVE-2023-39240?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2023-39240?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST