Several security issues were fixed in NTP.
Neel Mehta discovered that NTP generated weak authentication keys. A remote attacker could possibly use this issue to brute force the authentication key and send requests if permitted by IP restrictions. (CVE-2014-9293)
22 December 2014
A security issue affects these releases of Ubuntu and its derivatives:
Several security issues were fixed in NTP.
Neel Mehta discovered that NTP generated weak authentication keys. A remote attacker could possibly use this issue to brute force the authentication key and send requests if permitted by IP restrictions. (CVE-2014-9293)
Stephen Roettger discovered that NTP generated weak MD5 keys. A remote attacker could possibly use this issue to brute force the MD5 key and spoof a client or server. (CVE-2014-9294)
Stephen Roettger discovered that NTP contained buffer overflows in the crypto_recv(), ctl_putdata() and configure() functions. In non-default configurations, a remote attacker could use these issues to cause NTP to crash, resulting in a denial of service, or possibly execute arbitrary code. The default compiler options for affected releases should reduce the vulnerability to a denial of service. In addition, attackers would be isolated by the NTP AppArmor profile. (CVE-2014-9295)
Stephen Roettger discovered that NTP incorrectly continued processing when handling certain errors. (CVE-2014-9296)
The problem can be corrected by updating your system to the following package versions:
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
After a standard system update you need to regenerate any MD5 keys that were manually created with ntp-keygen.
Vulmon