CVE-2015-7871

Crypto-NAK packets in ntpd in NTP 4.2.x before 4.2.8p4, and 4.3.x before 4.3.77 allows remote attackers to bypass authentication.

It was found that ntpd did not correctly implement the threshold limitation for the '-g' option, which is used to set the time without any restrictions.

A man-in-the-middle attacker able to intercept NTP traffic between a connecting client and an NTP server could use this flaw to force that client to make multiple steps larger than the panic threshold, effectively changing the time to an arbitrary value at any time (CVE-2015-5300).

Slow memory leak in CRYPTO_ASSOC with autokey (CVE-2015-7701).

Incomplete autokey data packet length checks could result in crash caused by a crafted packet (CVE-2015-7691, CVE-2015-7692, CVE-2015-7702).

Clients that receive a KoD should validate the origin timestamp field (CVE-2015-7704).

ntpq atoascii() Memory Corruption Vulnerability could result in ntpd crash caused by a crafted packet (CVE-2015-7852).

Symmetric association authentication bypass via crypto-NAK (CVE-2015-7871).

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

This ntp update provides the following security and non security fixes:

• Update to 4.2.8p4 to fix several security issues (bsc#951608):
  • CVE-2015-7871: NAK to the Future: Symmetric association authentication bypass via crypto-NAK
  • CVE-2015-7855: decodenetnum() will ASSERT botch instead of returning FAIL on some bogus values
  • CVE-2015-7854: Password Length Memory Corruption Vulnerability
  • CVE-2015-7853: Invalid length data provided by a custom refclock driver could cause a buffer overflow
  • CVE-2015-7852 ntpq atoascii() Memory Corruption Vulnerability
  • CVE-2015-7851 saveconfig Directory Traversal Vulnerability
  • CVE-2015-7850 remote config logfile-keyfile
  • CVE-2015-7849 trusted key use-after-free
  • CVE-2015-7848 mode 7 loop counter underrun
  • CVE-2015-7701 Slow memory leak in CRYPTO_ASSOC
  • CVE-2015-7703 configuration directives 'pidfile' and 'driftfile' should only be allowed locally
  • CVE-2015-7704, CVE-2015-7705 Clients that receive a KoD should validate the origin timestamp field
  • CVE-2015-7691, CVE-2015-7692, CVE-2015-7702 Incomplete autokey data packet length checks
• Use ntpq instead of deprecated ntpdc in start-ntpd (bnc#936327).
• Add a controlkey to ntp.conf to make the above work.
• Improve runtime configuration:
  • Read keytype from ntp.conf
  • Don't write ntp keys to syslog.
• Don't let 'keysdir' lines in ntp.conf trigger the 'keys' parser.
• Fix the comment regarding addserver in ntp.conf (bnc#910063).
• Remove ntp.1.gz, it wasn't installed anymore.
• Remove ntp-4.2.7-rh-manpages.tar.gz and only keep ntptime.8.gz. The rest is partially irrelevant, partially redundant and potentially outdated (bsc#942587).
• Remove 'kod' from the restrict line in ntp.conf (bsc#944300).
• Use SHA1 instead of MD5 for symmetric keys (bsc#905885).
• Require perl-Socket6 (bsc#942441).
• Fix incomplete backporting of 'rcntp ntptimemset'.

ntp was updated to version 4.2.8p6 to fix 28 security issues.

Major functional changes:

• The 'sntp' commandline tool changed its option handling in a major way, some options have been renamed or dropped.
• '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.

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

These security issues were fixed:

• 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 configuration:
  • Read keytype from ntp.conf
  • Don't write ntp keys to syslog. -…

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.