RHSA-2016:0780 - Security Advisory

Topic

An update for ntp is now available for Red Hat Enterprise Linux 6.

Red Hat Product Security has rated this update as having a security impact of Moderate. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Description

The Network Time Protocol (NTP) is used to synchronize a computer's time with another referenced time source. These packages include the ntpd service which continuously adjusts system time and utilities used to query and configure the ntpd service.

Security Fix(es):

• It was found that the fix for CVE-2014-9750 was incomplete: three issues were found in the value length checks in NTP's ntp_crypto.c, where a packet with particular autokey operations that contained malicious data was not always being completely validated. A remote attacker could use a specially crafted NTP packet to crash ntpd. (CVE-2015-7691, CVE-2015-7692, CVE-2015-7702)
• A memory leak flaw was found in ntpd's CRYPTO_ASSOC. If ntpd was configured to use autokey authentication, an attacker could send packets to ntpd that would, after several days of ongoing attack, cause it to run out of memory. (CVE-2015-7701)
• An off-by-one flaw, leading to a buffer overflow, was found in cookedprint functionality of ntpq. A specially crafted NTP packet could potentially cause ntpq to crash. (CVE-2015-7852)
• A NULL pointer dereference flaw was found in the way ntpd processed 'ntpdc reslist' commands that queried restriction lists with a large amount of entries. A remote attacker could potentially use this flaw to crash ntpd. (CVE-2015-7977)
• A stack-based buffer overflow flaw was found in the way ntpd processed 'ntpdc reslist' commands that queried restriction lists with a large amount of entries. A remote attacker could use this flaw to crash ntpd. (CVE-2015-7978)
• It was found that ntpd could crash due to an uninitialized variable when processing malformed logconfig configuration commands. (CVE-2015-5194)
• It was found that ntpd would exit with a segmentation fault when a statistics type that was not enabled during compilation (e.g. timingstats) was referenced by the statistics or filegen configuration command. (CVE-2015-5195)
• It was discovered that the sntp utility could become unresponsive due to being caught in an infinite loop when processing a crafted NTP packet. (CVE-2015-5219)
• It was found that NTP's :config command could be used to set the pidfile and driftfile paths without any restrictions. A remote attacker could use this flaw to overwrite a file on the file system with a file containing the pid of the ntpd process (immediately) or the current estimated drift of the system clock (in hourly intervals). (CVE-2015-7703)

The CVE-2015-5219 and CVE-2015-7703 issues were discovered by Miroslav Lichvár (Red Hat).

For detailed information on changes in this release, see the Red Hat Enterprise Linux 6.8 Release Notes and Red Hat Enterprise Linux 6.8 Technical Notes linked from the References section.

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

Affected Products

• Red Hat Enterprise Linux Server 6 x86_64
• Red Hat Enterprise Linux Server 6 i386
• Red Hat Enterprise Linux Workstation 6 i386
• Red Hat Enterprise Linux for IBM z Systems 6 s390x
• Red Hat Enterprise Linux for Power, big endian 6 ppc64
• Red Hat Enterprise Linux for Scientific Computing 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 i386
• Red Hat Enterprise Linux Workstation 6 x86_64
• Red Hat Enterprise Linux Desktop 6 x86_64
• Red Hat Enterprise Linux Desktop 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 6 s390x
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension (for IBM z Systems) 6 s390x

Fixes

• BZ - 1254542 - CVE-2015-5194 ntp: crash with crafted logconfig configuration command
• BZ - 1254544 - CVE-2015-5195 ntp: ntpd crash when processing config commands with statistics type
• BZ - 1254547 - CVE-2015-7703 ntp: config command can be used to set the pidfile and drift file paths
• BZ - 1255118 - CVE-2015-5219 ntp: infinite loop in sntp processing crafted packet
• BZ - 1274254 - CVE-2015-7691 CVE-2015-7692 CVE-2015-7702 ntp: incomplete checks in ntp_crypto.c
• BZ - 1274255 - CVE-2015-7701 ntp: slow memory leak in CRYPTO_ASSOC
• BZ - 1274261 - CVE-2015-7852 ntp: ntpq atoascii memory corruption vulnerability
• BZ - 1286969 - ntpstat reports synchronized even when the local ntpd doesn't synchronize with any time server.
• BZ - 1300269 - CVE-2015-7977 ntp: restriction list NULL pointer dereference
• BZ - 1300270 - CVE-2015-7978 ntp: stack exhaustion in recursive traversal of restriction list

CVEs

• CVE-2015-5194
• CVE-2015-5195
• CVE-2015-5219
• CVE-2015-7691
• CVE-2015-7692
• CVE-2015-7701
• CVE-2015-7702
• CVE-2015-7703
• CVE-2015-7852
• CVE-2015-7977
• CVE-2015-7978

References

• http://www.redhat.com/security/updates/classification/#normal