chrony - security update

Miroslav Lichvar of Red Hat discovered multiple vulnerabilities in chrony,
an alternative NTP client and server:

• 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 1.30-2.

We recommend that you upgrade your chrony packages.