Published: 26 March 2018
In Apache httpd 2.0.23 to 2.0.65, 2.2.0 to 2.2.34, and 2.4.0 to 2.4.29, mod_authnz_ldap, if configured with AuthLDAPCharsetConfig, uses the Accept-Language header value to lookup the right charset encoding when verifying the user's credentials. If the header value is not present in the charset conversion table, a fallback mechanism is used to truncate it to a two characters value to allow a quick retry (for example, 'en-US' is truncated to 'en'). A header value of less than two characters forces an out of bound write of one NUL byte to a memory location that is not part of the string. In the worst case, quite unlikely, the process would crash which could be used as a Denial of Service attack. In the more likely case, this memory is already reserved for future use and the issue has no effect at all.
CVSS 3 base score: 7.5
Launchpad, Ubuntu, Debian
|Ubuntu 18.04 LTS (Bionic Beaver)||
|Ubuntu 16.04 LTS (Xenial Xerus)||
|Ubuntu 14.04 ESM (Trusty Tahr)||
Upstream: http://svn.apache.org/viewvc?view=revision&revision=1824456 (2.4)