CVE-2023-29596

Vulnerability

A buffer overflow vulnerability exists in ByronKnoll Cmix version 19 in the paq8 function, specifically in FrenchStemmer::ConvertUTF8 at paq8.cpp:2502. The issue is triggered when processing a specially crafted input file with the -n flag, resulting in a memcpy-param-overlap condition as detected by AddressSanitizer [1].

Exploitation

An attacker can exploit this vulnerability by providing a malicious input file to cmix with the -n parameter. No authentication or special privileges are required, but local access to execute the binary is necessary. The crash occurs during compression, as shown in the backtrace: FrenchStemmer::ConvertUTF8 calls __asan_memcpy with overlapping memory ranges [1].

Impact

Successful exploitation can cause a denial of service (DoS) due to program crash. The description also indicates potential for arbitrary code execution, as memory corruption from a buffer overflow can be leveraged to execute attacker-controlled code, though no proof-of-concept is provided in the reference [1].

Mitigation

As of the reference date, no official patch or fix has been released. Users are advised to avoid using the -n flag with untrusted input files or to monitor the project for updates [1].