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.
Platform | Package | Release Date | Advisory |
---|---|---|---|
Amazon Linux 1 | httpd24 | 2018-05-03 16:29 | ALAS-2018-1004 |
Score Type | Score | Vector | |
---|---|---|---|
Amazon Linux | CVSSv3 | 5.9 | CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H |
NVD | CVSSv2 | 5.0 | AV:N/AC:L/Au:N/C:N/I:N/A:P |
NVD | CVSSv3 | 7.5 | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |