CVE-2013-1923

rpc-gssd en nfs-utils anterior a la versión 1.2.8 realiza resoluciones inversas de DNS en nombres de servidor durante la autenticación GSSAPI, lo que podría permitir a atacantes remotos leer archivos restringidos del mismo modo a través de ataques de falsificación de DNS.

Updated nfs-utils packages fix a security vulnerability. It was reported that rpc.gssd in nfs-utils is vulnerable to DNS spoofing due to it depending on PTR resolution for GSSAPI authentication. Because of this, if a user where able to poison DNS to a victim's computer, they would be able to trick rpc.gssd into talking to another server than the intended server (with stricter security). If the victim has write access to the second server, and the attacker has read access (when they normally might not on the secure server), the victim could write files to that server, which the attacker could obtain (when normally they would not be able to). To the victim this is transparent because the victim's computer asks the KDC for a ticket to the second server due to reverse DNS resolution; in this case Krb5 authentication does not fail because the victim is talking to the correct server.