Jakob Hirsch

The issue is related to the mod authnz ldap component in Apache httpd, specifically when configured with AuthLDAPCharsetConfig. It uses the Accept-Language header value to determine the correct charset encoding for user credential verification. If the header value is not found in the charset conversion table, it is truncated to a two-character value. A header value with less than two characters can cause an out-of-bounds write of a NUL byte to a memory location, potentially leading to a Denial of Service attack, although this is unlikely. In most cases, the memory is already reserved for future use, and the issue has no effect.

Name of the Vulnerable Software and Affected Versions: Apache HTTP Server versions 2.4.54 and earlier Description: A carefully crafted If: request header can cause a memory read, or write of a single zero byte, in a pool (heap) memory location beyond the header value sent. This could cause the process to crash. The issue is also related to a buffer overflow in the mod dav module, which can allow a remote attacker to cause a denial of service. Recommendations: For Apache HTTP Server versions 2.4.54 and earlier, update to a version later than 2.4.54 to resolve the issue. As a temporary workaround, consider restricting access to the If: request header to minimize the risk of exploitation. Additionally, restricting access to the mod dav module can also help mitigate the risk of a denial of service attack.