Debian Security Advisory

DLA-559-1 ntp -- LTS security update

Date Reported:
25 Jul 2016
Affected Packages:
Security database references:
In Mitre's CVE dictionary: CVE-2015-7974, CVE-2015-7977, CVE-2015-7978, CVE-2015-7979, CVE-2015-8138, CVE-2015-8158, CVE-2016-1547, CVE-2016-1548, CVE-2016-1550, CVE-2016-2516, CVE-2016-2518.
More information:

Several vulnerabilities were discovered in the Network Time Protocol daemon and utility programs:

  • CVE-2015-7974

    Matt Street discovered that insufficient key validation allows impersonation attacks between authenticated peers.

  • CVE-2015-7977 / CVE-2015-7978

    Stephen Gray discovered that a NULL pointer dereference and a buffer overflow in the handling of ntpdc reslist commands may result in denial of service.

  • CVE-2015-7979

    Aanchal Malhotra discovered that if NTP is configured for broadcast mode, an attacker can send malformed authentication packets which break associations with the server for other broadcast clients.

  • CVE-2015-8138

    Matthew van Gundy and Jonathan Gardner discovered that missing validation of origin timestamps in ntpd clients may result in denial of service.

  • CVE-2015-8158

    Jonathan Gardner discovered that missing input sanitising in ntpq may result in denial of service.

  • CVE-2016-1547

    Stephen Gray and Matthew van Gundy discovered that incorrect handling of crypto NAK packets my result in denial of service.

  • CVE-2016-1548

    Jonathan Gardner and Miroslav Lichvar discovered that ntpd clients could be forced to change from basic client/server mode to interleaved symmetric mode, preventing time synchronisation.

  • CVE-2016-1550

    Matthew van Gundy, Stephen Gray and Loganaden Velvindron discovered that timing leaks in the the packet authentication code could result in recovery of a message digest.

  • CVE-2016-2516

    Yihan Lian discovered that duplicate IPs on unconfig directives will trigger an assert.

  • CVE-2016-2518

    Yihan Lian discovered that an OOB memory access could potentially crash ntpd.

For Debian 7 Wheezy, these problems have been fixed in version 1:4.2.6.p5+dfsg-2+deb7u7.

We recommend that you upgrade your ntp packages.

Further information about Debian LTS security advisories, how to apply these updates to your system and frequently asked questions can be found at: