CVE-2015-1798

Updated ntp packages fix security vulnerabilities:

The symmetric-key feature in the receive function in ntp_proto.c in ntpd in NTP before 4.2.8p2 requires a correct MAC only if the MAC field has a nonzero length, which makes it easier for man-in-the-middle attackers to spoof packets by omitting the MAC (CVE-2015-1798).

The symmetric-key feature in the receive function in ntp_proto.c in ntpd in NTP before 4.2.8p2 performs state-variable updates upon receiving certain invalid packets, which makes it easier for man-in-the-middle attackers to cause a denial of service (synchronization loss) by spoofing the source IP address of a peer (CVE-2015-1799).

These are all security issues fixed in the ntp-4.2.8p9-1.1 package on the GA media of openSUSE Tumbleweed.

ntp was updated to fix two security related flaws as well as 'slew' mode handling for leap seconds.

The following vulnerabilities were fixe:

• ntpd could accept unauthenticated packets with symmetric key crypto. (CVE-2015-1798)
• ntpd authentication did not protect symmetric associations against DoS attacks (CVE-2015-1799)
• ntp-keygen may generate non-random symmetric keys on big-endian systems (bsc#928321, CVE-2015-3405).

The following non-security issues were fixed:

• Fix slew mode for leap seconds (bnc#918342).

The symmetric-key feature in the receive function in ntp_proto.c in ntpd in NTP 4.x before 4.2.8p2 requires a correct MAC only if the MAC field has a nonzero length, which makes it easier for man-in-the-middle attackers to spoof packets by omitting the MAC.

Miroslav Lichvar discovered that NTP incorrectly validated MAC fields. A remote attacker could possibly use this issue to bypass authentication and spoof packets. (CVE-2015-1798)

Miroslav Lichvar discovered that NTP incorrectly handled certain invalid packets. A remote attacker could possibly use this issue to cause a denial of service. (CVE-2015-1799)

Juergen Perlinger discovered that NTP incorrectly generated MD5 keys on big-endian platforms. This issue could either cause ntp-keygen to hang, or could result in non-random keys. (CVE number pending)