Debian: DSA-3222-1 Critical: Chrony DoS and Code Execution Risks

CVE-2015-1821

Using particular address/subnet pairs when configuring access control
would cause an invalid memory write. This could allow attackers to
cause a denial of service (crash) or execute arbitrary code.

CVE-2015-1822

When allocating memory to save unacknowledged replies to authenticated
command requests, a pointer would be left uninitialized, which could
trigger an invalid memory write. This could allow attackers to cause a
denial of service (crash) or execute arbitrary code.

CVE-2015-1853

When peering with other NTP hosts using authenticated symmetric
association, the internal state variables would be updated 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.

For the stable distribution (wheezy), these problems have been fixed in
version 1.24-3.1+deb7u3.

For the unstable distribution (sid), these problems have been fixed in
version 1.3...