Multiple vulnerabilities were discovered in ntp, an implementation of the Network Time Protocol: CVE-2015-1798 When configured to use a symmetric key with an NTP peer, ntpd would accept packets without MAC as if they had a valid MAC. This could allow a remote attacker to bypass the packet authentication and send malicious packets without having to know the symmetric key. CVE-2015-1799 When peering with other NTP hosts using authenticated symmetric association, ntpd would update its internal state variables before the MAC of the NTP messages was validated. This could allow a remote attacker to cause a denial of service by impeding synchronization between NTP peers. Additionally, it was discovered that generating MD5 keys using ntp-keygen on big endian machines would either trigger an endless loop, or generate non-random keys. For the stable distribution (wheezy), these problems have been fixed in version 1:4.2.6.p5+dfsg-2+deb7u4. For the unstable distribution (sid), these problems have been fixed in version 1:4.2.6.p5+dfsg-7. We recommend that you upgrade your ntp packages.
Multiple vulnerabilities were discovered in ntp, an implementation of the Network Time Protocol:
When configured to use a symmetric key with an NTP peer, ntpd would accept packets without MAC as if they had a valid MAC. This could allow a remote attacker to bypass the packet authentication and send malicious packets without having to know the symmetric key.
When peering with other NTP hosts using authenticated symmetric association, ntpd would update its internal state variables before the MAC of the NTP messages was validated. This could allow a remote attacker to cause a denial of service by impeding synchronization between NTP peers.
Additionally, it was discovered that generating MD5 keys using ntp-keygen on big endian machines would either trigger an endless loop, or generate non-random keys.
For the stable distribution (wheezy), these problems have been fixed in version 1:4.2.6.p5+dfsg-2+deb7u4.
For the unstable distribution (sid), these problems have been fixed in version 1:4.2.6.p5+dfsg-7.
We recommend that you upgrade your ntp packages.