Debian NTP Critical Denial of Service Advisory DSA-3223-1 CVE-2015-1798

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 ...