Apache · Apache Httpd · CVE-2017-15710
**Name of the Vulnerable Software and Affected Versions**
Apache httpd versions 2.0.23 through 2.0.65
Apache httpd versions 2.2.0 through 2.2.34
Apache httpd versions 2.4.0 through 2.4.29
**Description**
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.
**Recommendations**
For Apache httpd versions 2.0.23 through 2.0.65, consider disabling the AuthLDAPCharsetConfig to prevent the issue until a patch is available.
For Apache httpd versions 2.2.0 through 2.2.34, consider disabling the AuthLDAPCharsetConfig to prevent the issue until a patch is available.
For Apache httpd versions 2.4.0 through 2.4.29, consider disabling the AuthLDAPCharsetConfig to prevent the issue until a patch is available.
As a temporary workaround, consider restricting access to the `Accept-Language` header to minimize the risk of exploitation.