PT-2022-11252 · Asus · Asus Rt-Ax56U Router

X1Ng · Published 2022-10-06 · Updated 2022-10-07 · CVE-2021-40556

Positive Technologies (AI Summary)

CVSS v3.1

8.8

High

Base vector

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

Name of the Vulnerable Software and Affected Versions ASUS RT-AX56U Router version 3.0.0.4.386.44266

Description A stack overflow issue exists in the httpd service, caused by the strcat function called by the caupload input handle function, allowing users to enter a large amount of data into the stack. This issue enables an attacker to execute commands remotely, but it requires authentication.

Recommendations For version 3.0.0.4.386.44266, as a temporary workaround, consider restricting access to the caupload input handle function until a patch is available. At the moment, there is no information about a newer version that contains a fix for this issue.

Exploit

Fix

Memory Corruption

Weakness Enumeration

CWE-787

Related Identifiers

CVE-2021-40556

Affected Products

Asus Rt-Ax56U Router

References · 4

• 🔥 https://x1ng.top/2021/10/14/ASUS%E6%A0%88%E6%BA%A2%E5%87%BA%E6%BC%8F%E6%B4%9E%E5%88%86%E6%9E%90 · Exploit
• https://nvd.nist.gov/vuln/detail/CVE-2021-40556 · Security Note
• https://asus.com/tw/Networking-IoT-Servers/WiFi-Routers/ASUS-WiFi-Routers/RT-AX56U/HelpDesk_BIOS · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2021-40556 · Vendor Advisory