CVE-2015-7974

NTP 4.x en versiones anteriores a 4.2.8p6 y 4.3.x en versiones anteriores a 4.3.90 no verifica las asociaciones del par de las claves simétricas cuando autentica paquetes, lo que podría permitir a atacante remotos llevar a cabo ataques de suplantación de identidad a través de una clave de confianza arbitraria, también conocida como "skeleton key".

A flaw was found in the way NTP verified trusted keys during symmetric key authentication. An authenticated client (A) could use this flaw to modify a packet sent between a server (B) and a client (C) using a key that is different from the one known to the client (A).

The Network Time Protocol is used to synchronize a computer's time with another referenced time source. These packages include the ntpd service which continuously adjusts system time and utilities used to query and configure the ntpd service. Security Fix: It was found that the fix for CVE-2014-9750 was incomplete: three issues were found in the value length checks in NTP's ntp_crypto.c, where a packet with particular autokey operations that contained malicious data was not always being completely validated. A remote attacker could use a specially crafted NTP packet to crash ntpd.