7.8 - RHSA-2016:2583

Problem Description:

An update for ntp is now available for Red Hat Enterprise Linux 7.

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.

2. Relevant releases/architectures:

Red Hat Enterprise Linux Client (v. 7) - x86_64 Red Hat Enterprise Linux Client Optional (v. 7) - noarch, x86_64 Red Hat Enterprise Linux ComputeNode (v. 7) - x86_64 Red Hat Enterprise Linux ComputeNode Optional (v. 7) - noarch, x86_64 Red Hat Enterprise Linux Server (v. 7) - aarch64, ppc64, ppc64le, s390x, x86_64 Red Hat Enterprise Linux Server Optional (v. 7) - aarch64, noarch, ppc64, ppc64le, s390x, x86_64 Red Hat Enterprise Linux Workstation (v. 7) - x86_64 Red Hat Enterprise Linux Workstation Optional (v. 7) - noarch, x86_64

3. 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 when NTP was configured in broadcast mode, a remote attacker could broadcast packets with bad authentication to all clients. The clients, upon receiving the malformed packets, would break the association with the broadcast server, causing them to become out of sync over a longer period of time. (CVE-2015-7979)

* 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 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-2015-5196, CVE-2015-7703)

* 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)

* A flaw was found in the way NTP verified trusted keys during symmetric key authentication. An authenticated client (A) could use this flaw to modify a packet sent between a server (B) and a client (C) using a key that is different from the one known to the client (A). (CVE-2015-7974)

* A flaw was found in the way the ntpq client processed certain incoming packets in a loop in the getresponse() function. A remote attacker could potentially use this flaw to crash an ntpq client instance. (CVE-2015-8158)

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

Additional Changes:

For detailed information on changes in this release, see the Red Hat Enterprise Linux 7.3 Release Notes linked from the References section.

4. 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

After installing this update, the ntpd daemon will restart automatically.

5. Bugs fixed (https://bugzilla.redhat.com/):

1242553 - ntpd doesn't reset system leap status when disarming leap timer 1254542 - CVE-2015-5194 ntp: crash with crafted logconfig configuration command 1254544 - CVE-2015-5195 ntp: ntpd crash when processing config commands with statistics type 1254547 - CVE-2015-7703 ntp: config command can be used to set the pidfile and drift file paths 1255118 - CVE-2015-5219 ntp: infinite loop in sntp processing crafted packet 1274254 - CVE-2015-7691 CVE-2015-7692 CVE-2015-7702 ntp: incomplete checks in ntp_crypto.c 1274255 - CVE-2015-7701 ntp: slow memory leak in CRYPTO_ASSOC 1274261 - CVE-2015-7852 ntp: ntpq atoascii memory corruption vulnerability 1297471 - CVE-2015-7974 ntp: missing key check allows impersonation between authenticated peers (VU#357792) 1300269 - CVE-2015-7977 ntp: restriction list NULL pointer dereference 1300270 - CVE-2015-7978 ntp: stack exhaustion in recursive traversal of restriction list 1300271 - CVE-2015-7979 ntp: off-path denial of service on authenticated broadcast mode 1300273 - CVE-2015-8158 ntp: potential infinite loop in ntpq