CVE-2017-15710: Out of bound write in mod_authnz_ldap when using too small Accept-Language values.
Severity: Low Vendor: The Apache Software Foundation Versions Affected: httpd 2.0.23 to 2.0.65 httpd 2.2.0 to 2.2.34 httpd 2.4.0 to 2.4.29 Description: 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." Mitigation: All httpd users should upgrade to 2.4.30 or later. Users of (the now end-of-life) httpd 2.2 who cannot upgrade at this time should apply CVE-2017-15710.patch, which is available at https://www.apache.org/dist/httpd/patches/apply_to_2.2.34/ Credit: The Apache HTTP Server security team would like to thank Alex Nichols and Jakob Hirsch for reporting this issue. References: https://httpd.apache.org/security/vulnerabilities_24.html