CVE-2015-7979

NTP before 4.2.8p6 and 4.3.x before 4.3.90 allows remote attackers to cause a denial of service (client-server association tear down) by sending broadcast packets with invalid authentication to a broadcast client.

In ntpd before 4.2.8p6, when used with symmetric key encryption, the client would accept packets encrypted with keys for any configured server, allowing a server to impersonate other servers to clients, thus performing a man-in-the-middle attack. A server can be attacked by a client in a similar manner (CVE-2015-7974).

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 use this flaw to crash the ntpd process (CVE-2015-7977).

A stack-based buffer overflow 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 the ntpd process (CVE-2015-7978).

It was found that when NTP is configured in broadcast mode, an off-path attacker could broadcast packets with bad authentication (wrong key, mismatched key, incorrect MAC, etc) to all clients. The clients, upon receiving the malformed packets, would break the association with the broadcast server. This could cause the time on affected clients to become out of sync over a longer period of time (CVE-2015-7979).

A faulty protection against spoofing and replay attacks allows an attacker to disrupt synchronization with kiss-of-death packets, take full control of the clock, or cause ntpd to crash (CVE-2015-8138).

A flaw was found in the way the ntpq client certain processed 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 ntp package has been patched to fix these issues and a few other bugs.

Note that there are still some unfixed issues. Two of those issues, CVE-2015-8139 and CVE-2015-8140, are vulnerabilities to spoofing and replay attacks that can be mitigated by either adding the noquery option to all restrict entries in ntp.conf, configuring ntpd to get time from multiple sources, or using a restriction list to limit who is allowed to issue ntpq and ntpdc queries.

Additionally, the other unfixed issues can also be mitigated. CVE-2015-7973, a replay attack issue, can be mitigated by not using broadcast mode, and CVE-2015-7976, a bug that can cause globbing issues on the server, can be mitigated by restricting use of the "saveconfig" command with the "restrict nomodify" directive.

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

ntp was updated to version 4.2.8p6 to fix 12 security issues.

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).

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.
• bsc#784760: Remove local clock from default configuration

ntp was updated to version 4.2.8p6 to fix 12 security issues.

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).

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.

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…

Aanchal Malhotra discovered that NTP incorrectly handled authenticated broadcast mode. A remote attacker could use this issue to perform a replay attack. (CVE-2015-7973)

Matt Street discovered that NTP incorrectly verified peer associations of symmetric keys. A remote attacker could use this issue to perform an impersonation attack. (CVE-2015-7974)

Jonathan Gardner discovered that the NTP ntpq utility incorrectly handled memory. An attacker could possibly use this issue to cause ntpq to crash, resulting in a denial of service. This issue only affected Ubuntu 16.04 LTS. (CVE-2015-7975)

Jonathan Gardner discovered that the NTP ntpq utility incorrectly handled dangerous characters in filenames. An attacker could possibly use this issue to overwrite arbitrary files. (CVE-2015-7976)

Stephen Gray discovered that NTP incorrectly handled large restrict lists. An attacker could use this issue to cause NTP to crash, resulting in a denial of service. (CVE-2015-7977, CVE-2015-7978)

Aanchal Malhotra discovered that NTP incorrectly handled authenticated broadcast mode. A remote attacker could use this issue to cause NTP to crash, resulting in a denial of service. (CVE-2015-7979)

Jonathan Gardner discovered that NTP incorrectly handled origin timestamp checks. A remote attacker could use this issue to spoof peer servers. (CVE-2015-8138)

Jonathan Gardner discovered that the NTP ntpq utility did not properly handle certain incorrect values. An attacker could possibly use this issue to cause ntpq to hang, resulting in a denial of service. (CVE-2015-8158)

It was discovered that the NTP cronjob incorrectly cleaned up the statistics directory. A local attacker could possibly use this to escalate privileges. (CVE-2016-0727)

Stephen Gray and Matthew Van Gundy discovered that NTP incorrectly validated crypto-NAKs. A remote attacker could possibly use this issue to prevent clients from synchronizing. (CVE-2016-1547)

Miroslav Lichvar and Jonathan Gardner discovered that NTP incorrectly handled switching to interleaved symmetric mode. A remote attacker could possibly use this issue to prevent clients from synchronizing. (CVE-2016-1548)

Matthew Van Gundy, Stephen Gray and Loganaden Velvindron discovered that NTP incorrectly handled message authentication. A remote attacker could possibly use this issue to recover the message digest key. (CVE-2016-1550)

Yihan Lian discovered that NTP incorrectly handled duplicate IPs on unconfig directives. An authenticated remote attacker could possibly use this issue to cause NTP to crash, resulting in a denial of service. (CVE-2016-2516)

Yihan Lian discovered that NTP incorrectly handled certail peer associations. A remote attacker could possibly use this issue to cause NTP to crash, resulting in a denial of service. (CVE-2016-2518)

Jakub Prokes discovered that NTP incorrectly handled certain spoofed packets. A remote attacker could possibly use this issue to cause a denial of service. (CVE-2016-4954)

Miroslav Lichvar discovered that NTP incorrectly handled certain packets when autokey is enabled. A remote attacker could possibly use this issue to cause a denial of service. (CVE-2016-4955)

Miroslav Lichvar discovered that NTP incorrectly handled certain spoofed broadcast packets. A remote attacker could possibly use this issue to cause a denial of service. (CVE-2016-4956)

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