CVE-2015-5194

The log_config_command function in ntp_parser.y in ntpd in NTP before 4.2.7p42 allows remote attackers to cause a denial of service (ntpd crash) via crafted logconfig commands.

Updated ntp packages fix security vulnerability:

A flaw was found in the way ntpd processed certain remote configuration packets. An attacker could use a specially crafted package to cause ntpd to crash if the attacker had authenticated access to remote ntpd configuration (CVE-2015-5146).

It was found that ntpd could crash due to an uninitialized variable when processing malformed logconfig configuration commands, for example, ntpq -c ":config logconfig a" (CVE-2015-5194).

It was found that ntpd exits with a segmentation fault when a statistics type that was not enabled during compilation (e.g. timingstats) is referenced by the statistics or filegen configuration command, for example, ntpq -c ':config statistics timingstats' ntpq -c ':config filegen timingstats' (CVE-2015-5195).

It was found that the :config command can 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). For example, ntpq -c ':config pidfile /tmp/ntp.pid' ntpq -c ':config driftfile /tmp/ntp.drift' (CVE-2015-5196).

It was discovered that sntp would hang in an infinite loop when a crafted NTP packet was received, related to the conversion of the precision value in the packet to double (CVE-2015-5219).

This network time protocol server ntp was updated to 4.2.8p6 to fix the following issues:

Also yast2-ntp-client was updated to match some sntp syntax changes. (bsc#937837)

Major functional changes:

• The 'sntp' commandline tool changed its option handling in a major way.
• 'controlkey 1' is added during update to ntp.conf to allow sntp to work.
• The local clock is being disabled during update.
• ntpd is no longer running chrooted.

Other functional changes:

• ntp-signd is installed.
• 'enable mode7' can be added to the configuration to allow ntdpc to work as compatibility mode option.
• 'kod' was removed from the default restrictions.
• SHA1 keys are used by default instead of MD5 keys.

These security issues were fixed:

• CVE-2015-5219: An endless loop due to incorrect precision to double conversion (bsc#943216).
• CVE-2015-8158: Fixed potential infinite loop in ntpq (bsc#962966).
• CVE-2015-8138: Zero Origin Timestamp Bypass (bsc#963002).
• CVE-2015-7979: Off-path Denial of Service (DoS) attack on authenticated broadcast mode (bsc#962784).
• CVE-2015-7978: Stack exhaustion in recursive traversal of restriction list (bsc#963000).
• CVE-2015-7977: reslist NULL pointer dereference (bsc#962970).
• CVE-2015-7976: ntpq saveconfig command allows dangerous characters in filenames (bsc#962802).
• CVE-2015-7975: nextvar() missing length check (bsc#962988).
• CVE-2015-7974: Skeleton Key: Missing key check allows impersonation between authenticated peers (bsc#962960).
• CVE-2015-7973: Replay attack on authenticated broadcast mode (bsc#962995).
• CVE-2015-8140: ntpq vulnerable to replay attacks (bsc#962994).
• CVE-2015-8139: Origin Leak: ntpq and ntpdc, disclose origin (bsc#962997).
• CVE-2015-5300: MITM attacker could have forced ntpd to make a step larger than the panic threshold (bsc#951629).
• CVE-2015-7871: NAK to the Future: Symmetric association authentication bypass via crypto-NAK (bsc#951608).
• CVE-2015-7855: decodenetnum() will ASSERT botch instead of returning FAIL on some bogus values (bsc#951608).
• CVE-2015-7854: Password Length Memory Corruption Vulnerability (bsc#951608).
• CVE-2015-7853: Invalid length data provided by a custom refclock driver could cause a buffer overflow (bsc#951608).
• CVE-2015-7852: ntpq atoascii() Memory Corruption Vulnerability (bsc#951608).
• CVE-2015-7851: saveconfig Directory Traversal Vulnerability (bsc#951608).
• CVE-2015-7850: remote config logfile-keyfile (bsc#951608).
• CVE-2015-7849: trusted key use-after-free (bsc#951608).
• CVE-2015-7848: mode 7 loop counter underrun (bsc#951608).
• CVE-2015-7701: Slow memory leak in CRYPTO_ASSOC (bsc#951608).
• CVE-2015-7703: configuration directives 'pidfile' and 'driftfile' should only be allowed locally (bsc#951608).
• CVE-2015-7704, CVE-2015-7705: Clients that receive a KoD should validate the origin timestamp field (bsc#951608).
• CVE-2015-7691, CVE-2015-7692, CVE-2015-7702: Incomplete autokey data packet length checks (bsc#951608).

These non-security issues were fixed:

• fate#320758 bsc#975981: Enable compile-time support for MS-SNTP (--enable-ntp-signd). This replaces the w32 patches in 4.2.4 that added the authreg directive.
• bsc#962318: Call /usr/sbin/sntp with full path to synchronize in start-ntpd. When run as cron job, /usr/sbin/ is not in the path, which caused the synchronization to fail.
• bsc#782060: Speedup ntpq.
• bsc#916617: Add /var/db/ntp-kod.
• bsc#956773: Add ntp-ENOBUFS.patch to limit a warning that might happen quite a lot on loaded systems.
• bsc#951559,bsc#975496: Fix the TZ offset output of sntp during DST.
• Add ntp-fork.patch and build with threads disabled to allow name resolution even when running chrooted.
• Add a controlkey line to /etc/ntp.conf if one does not already exist to allow runtime configuuration via ntpq.
• bsc#946386: Temporarily disable memlock to avoid problems due to high memory usage during name resolution.
• bsc#905885: Use SHA1 instead of MD5 for symmetric keys.
• Improve runtime…

Aleksis Kauppinen discovered that NTP incorrectly handled certain remote config packets. In a non-default configuration, a remote authenticated attacker could possibly use this issue to cause NTP to crash, resulting in a denial of service. (CVE-2015-5146)

Miroslav Lichvar discovered that NTP incorrectly handled logconfig directives. In a non-default configuration, a remote authenticated attacker could possibly use this issue to cause NTP to crash, resulting in a denial of service. (CVE-2015-5194)

Miroslav Lichvar discovered that NTP incorrectly handled certain statistics types. In a non-default configuration, a remote authenticated attacker could possibly use this issue to cause NTP to crash, resulting in a denial of service. (CVE-2015-5195)

Miroslav Lichvar discovered that NTP incorrectly handled certain file paths. In a non-default configuration, a remote authenticated attacker could possibly use this issue to cause NTP to crash, resulting in a denial of service, or overwrite certain files. (CVE-2015-5196, CVE-2015-7703)

Miroslav Lichvar discovered that NTP incorrectly handled certain packets. A remote attacker could possibly use this issue to cause NTP to hang, resulting in a denial of service. (CVE-2015-5219)

Aanchal Malhotra, Isaac E. Cohen, and Sharon Goldberg discovered that NTP incorrectly handled restarting after hitting a panic threshold. A remote attacker could possibly use this issue to alter the system time on clients. (CVE-2015-5300)

It was discovered that NTP incorrectly handled autokey data packets. A remote attacker could possibly use this issue to cause NTP to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2015-7691, CVE-2015-7692, CVE-2015-7702)

It was discovered that NTP incorrectly handled memory when processing certain autokey messages. A remote attacker could possibly use this issue to cause NTP to consume memory, resulting in a denial of service. (CVE-2015-7701)

Aanchal Malhotra, Isaac E. Cohen, and Sharon Goldberg discovered that NTP incorrectly handled rate limiting. A remote attacker could possibly use this issue to cause clients to stop updating their clock. (CVE-2015-7704, CVE-2015-7705)

Yves Younan discovered that NTP incorrectly handled logfile and keyfile directives. In a non-default configuration, a remote authenticated attacker could possibly use this issue to cause NTP to enter a loop, resulting in a denial of service. (CVE-2015-7850)

Yves Younan and Aleksander Nikolich discovered that NTP incorrectly handled ascii conversion. A remote attacker could possibly use this issue to cause NTP to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2015-7852)

Yves Younan discovered that NTP incorrectly handled reference clock memory. A malicious refclock could possibly use this issue to cause NTP to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2015-7853)

John D "Doug" Birdwell discovered that NTP incorrectly handled decoding certain bogus values. An attacker could possibly use this issue to cause NTP to crash, resulting in a denial of service. (CVE-2015-7855)

Stephen Gray discovered that NTP incorrectly handled symmetric association authentication. A remote attacker could use this issue to possibly bypass authentication and alter the system clock. (CVE-2015-7871)

In the default installation, attackers would be isolated by the NTP AppArmor profile.