Vulnerabilities > CVE-2023-35086 - Use of Externally-Controlled Format String vulnerability in Asus Rt-Ac86U Firmware and Rt-Ax56U V2 Firmware
It is identified a format string vulnerability in ASUS RT-AX56U V2 & RT-AC86U. This vulnerability is caused by directly using input as a format string when calling syslog in logmessage_normal function, in the do_detwan_cgi module of httpd. An unauthenticated remote attacker without privilege can exploit this vulnerability to perform remote arbitrary code execution, arbitrary system operation or disrupt service. This issue affects RT-AX56U V2: 184.108.40.206.386_50460; RT-AC86U: 220.127.116.11_386_51529.
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Format String Injection An attacker includes formatting characters in a string input field on the target application. Most applications assume that users will provide static text and may respond unpredictably to the presence of formatting character. For example, in certain functions of the C programming languages such as printf, the formatting character %s will print the contents of a memory location expecting this location to identify a string and the formatting character %n prints the number of DWORD written in the memory. An attacker can use this to read or write to memory locations or files, or simply to manipulate the value of the resulting text in unexpected ways. Reading or writing memory may result in program crashes and writing memory could result in the execution of arbitrary code if the attacker can write to the program stack.
- String Format Overflow in syslog() This attack targets the format string vulnerabilities in the syslog() function. An attacker would typically inject malicious input in the format string parameter of the syslog function. This is a common problem, and many public vulnerabilities and associated exploits have been posted.