High severity · published Oct 6, 2022
CVE-2021-40556
A stack overflow vulnerability exists in the httpd service in ASUS RT-AX56U Router Version 3.0.0.4.386.44266
8.8
CVSS
1.6%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)1.6% · higher than 76% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
RF
Rt-ax56u Firmware · Asus
3.0.0.4.386.44266 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-40556
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-40556
Product
https://www.asus.com/tw/Networking-IoT-Servers/WiFi-Routers/ASUS-WiFi-Routers/RT-AX56U/HelpDesk_BIOS/
Exploit
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/
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