CVE-2021-40556: asus rt-ax56u_firmware Out-of-bounds Write

Vulnerability summary

CVE-2021-40556 is a high (CVSS 8.8) Out-of-bounds Write vulnerability in asus rt-ax56u_firmware. EPSS estimates a 1.59% chance of exploitation in the next 30 days, higher than 75.3% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 06-10-2022
   PublishedVulnerability first disclosed.
2. 04-08-2024
   Last modifiedVulnerability information updated.

Description

A stack overflow vulnerability exists in the httpd service in ASUS RT-AX56U Router Version 3.0.0.4.386.44266. This vulnerability is caused by the strcat function called by "caupload" input handle function allowing the user to enter 0xFFFF bytes into the stack. This vulnerability allows an attacker to execute commands remotely. The vulnerability requires authentication.

• CWE-787Out-of-bounds WriteThe product writes data past the end, or before the beginning, of the intended buffer.