CVE-2016-7426

NTP before 4.2.8p9 rate limits responses received from the configured sources when rate limiting for all associations is enabled, which allows remote attackers to cause a denial of service (prevent responses from the sources) by sending responses with a spoofed source address.

When ntpd is configured with rate limiting for all associations (restrict default limited in ntp.conf), the limits are applied also to responses received from its configured sources. An attacker who knows the sources (e.g., from an IPv4 refid in server response) and knows the system is (mis)configured in this way can periodically send packets with spoofed source address to keep the rate limiting activated and prevent ntpd from accepting valid responses from its sources (CVE-2016-7426).

When ntpd receives a server response on a socket that corresponds to a different interface than was used for the request, the peer structure is updated to use the interface for new requests. If ntpd is running on a host with multiple interfaces in separate networks and the operating system doesn't check source address in received packets (e.g. rp_filter on Linux is set to 0), an attacker that knows the address of the source can send a packet with spoofed source address which will cause ntpd to select wrong interface for the source and prevent it from sending new requests until the list of interfaces is refreshed, which happens on routing changes or every 5 minutes by default. If the attack is repeated often enough (once per second), ntpd will not be able to synchronize with the source (CVE-2016-7429).

An exploitable configuration modification vulnerability exists in the control mode (mode 6) functionality of ntpd. If, against long-standing BCP recommendations, "restrict default noquery ..." is not specified, a specially crafted control mode packet can set ntpd traps, providing information disclosure and DDoS amplification, and unset ntpd traps, disabling legitimate monitoring. A remote, unauthenticated, network attacker can trigger this vulnerability (CVE-2016-9310).

If trap service, disabled by default, has been explicitly enabled, an attacker can send a specially crafted packet to cause a null pointer dereference that will crash ntpd, resulting in a denial of service (CVE-2016-9311).

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

This update for ntp fixes the following issues:

• Simplify ntpd's search for its own executable to prevent AppArmor warnings (bsc#956365).

Security issues fixed (update to 4.2.8p9):

• CVE-2016-9311, CVE-2016-9310, bsc#1011377: Mode 6 unauthenticated trap information disclosure and DDoS vector.
• CVE-2016-7427, bsc#1011390: Broadcast Mode Replay Prevention DoS.
• CVE-2016-7428, bsc#1011417: Broadcast Mode Poll Interval Enforcement DoS.
• CVE-2016-7431, bsc#1011395: Regression: 010-origin: Zero Origin Timestamp Bypass.
• CVE-2016-7434, bsc#1011398: Null pointer dereference in _IO_str_init_static_internal().
• CVE-2016-7429, bsc#1011404: Interface selection attack.
• CVE-2016-7426, bsc#1011406: Client rate limiting and server responses.
• CVE-2016-7433, bsc#1011411: Reboot sync calculation problem.
• CVE-2015-5219: An endless loop due to incorrect precision to double conversion (bsc#943216).
• CVE-2015-8140: ntpq vulnerable to replay attacks.
• CVE-2015-8139: Origin Leak: ntpq and ntpdc, disclose origin.
• CVE-2015-5219: An endless loop due to incorrect precision to double conversion (bsc#943216).

Non-security issues fixed:

• Fix a spurious error message.
• Other bugfixes, see /usr/share/doc/packages/ntp/ChangeLog.
• Fix a regression in 'trap' (bsc#981252).
• Reduce the number of netlink groups to listen on for changes to the local network setup (bsc#992606).
• Fix segfault in 'sntp -a' (bsc#1009434).
• Silence an OpenSSL version warning (bsc#992038).
• Make the resolver task change user and group IDs to the same values as the main task. (bsc#988028)

This update for ntp fixes the following issues:

ntp was updated to 4.2.8p9.

Security issues fixed:

• CVE-2016-9311, CVE-2016-9310, bsc#1011377: Mode 6 unauthenticated trap information disclosure and DDoS vector.
• CVE-2016-7427, bsc#1011390: Broadcast Mode Replay Prevention DoS.
• CVE-2016-7428, bsc#1011417: Broadcast Mode Poll Interval Enforcement DoS.
• CVE-2016-7431, bsc#1011395: Regression: 010-origin: Zero Origin Timestamp Bypass.
• CVE-2016-7434, bsc#1011398: Null pointer dereference in _IO_str_init_static_internal().
• CVE-2016-7429, bsc#1011404: Interface selection attack.
• CVE-2016-7426, bsc#1011406: Client rate limiting and server responses.
• CVE-2016-7433, bsc#1011411: Reboot sync calculation problem.
• CVE-2015-5219: An endless loop due to incorrect precision to double conversion (bsc#943216).

Non-security issues fixed:

• Fix a spurious error message.
• Other bugfixes, see /usr/share/doc/packages/ntp/ChangeLog.
• Fix a regression in 'trap' (bsc#981252).
• Reduce the number of netlink groups to listen on for changes to the local network setup (bsc#992606).
• Fix segfault in 'sntp -a' (bsc#1009434).
• Silence an OpenSSL version warning (bsc#992038).
• Make the resolver task change user and group IDs to the same values as the main task. (bsc#988028)
• Simplify ntpd's search for its own executable to prevent AppArmor warnings (bsc#956365).

This update for ntp fixes the following issues:

ntp was updated to 4.2.8p9.

Security issues fixed:

• CVE-2016-9311, CVE-2016-9310, bsc#1011377: Mode 6 unauthenticated trap information disclosure and DDoS vector.
• CVE-2016-7427, bsc#1011390: Broadcast Mode Replay Prevention DoS.
• CVE-2016-7428, bsc#1011417: Broadcast Mode Poll Interval Enforcement DoS.
• CVE-2016-7431, bsc#1011395: Regression: 010-origin: Zero Origin Timestamp Bypass.
• CVE-2016-7434, bsc#1011398: Null pointer dereference in _IO_str_init_static_internal().
• CVE-2016-7429, bsc#1011404: Interface selection attack.
• CVE-2016-7426, bsc#1011406: Client rate limiting and server responses.
• CVE-2016-7433, bsc#1011411: Reboot sync calculation problem.
• CVE-2015-5219: An endless loop due to incorrect precision to double conversion (bsc#943216).

Non-security issues fixed:

• Fix a spurious error message.
• Other bugfixes, see /usr/share/doc/packages/ntp/ChangeLog.
• Fix a regression in 'trap' (bsc#981252).
• Reduce the number of netlink groups to listen on for changes to the local network setup (bsc#992606).
• Fix segfault in 'sntp -a' (bsc#1009434).
• Silence an OpenSSL version warning (bsc#992038).
• Make the resolver task change user and group IDs to the same values as the main task. (bsc#988028)
• Simplify ntpd's search for its own executable to prevent AppArmor warnings (bsc#956365).

This update for ntp fixes the following issues:

ntp was updated to 4.2.8p9.

Security issues fixed:

• CVE-2016-9311, CVE-2016-9310, bsc#1011377: Mode 6 unauthenticated trap information disclosure and DDoS vector.
• CVE-2016-7427, bsc#1011390: Broadcast Mode Replay Prevention DoS.
• CVE-2016-7428, bsc#1011417: Broadcast Mode Poll Interval Enforcement DoS.
• CVE-2016-7431, bsc#1011395: Regression: 010-origin: Zero Origin Timestamp Bypass.
• CVE-2016-7434, bsc#1011398: Null pointer dereference in _IO_str_init_static_internal().
• CVE-2016-7429, bsc#1011404: Interface selection attack.
• CVE-2016-7426, bsc#1011406: Client rate limiting and server responses.
• CVE-2016-7433, bsc#1011411: Reboot sync calculation problem.
• CVE-2015-8140: ntpq vulnerable to replay attacks.
• CVE-2015-8139: Origin Leak: ntpq and ntpdc, disclose origin.
• CVE-2015-5219: An endless loop due to incorrect precision to double conversion (bsc#943216).

Non-security issues fixed:

• Fix a spurious error message.
• Other bugfixes, see /usr/share/doc/packages/ntp/ChangeLog.
• Fix a regression in 'trap' (bsc#981252).
• Reduce the number of netlink groups to listen on for changes to the local network setup (bsc#992606).
• Fix segfault in 'sntp -a' (bsc#1009434).
• Silence an OpenSSL version warning (bsc#992038).
• Make the resolver task change user and group IDs to the same values as the main task. (bsc#988028)
• Simplify ntpd's search for its own executable to prevent AppArmor warnings (bsc#956365).

Yihan Lian discovered that NTP incorrectly handled certain large request data values. A remote attacker could possibly use this issue to cause NTP to crash, resulting in a denial of service. This issue only affected Ubuntu 16.04 LTS. (CVE-2016-2519)

Miroslav Lichvar discovered that NTP incorrectly handled certain spoofed addresses when performing rate limiting. A remote attacker could possibly use this issue to perform a denial of service. This issue only affected Ubuntu 14.04 LTS, Ubuntu 16.04 LTS, and Ubuntu 16.10. (CVE-2016-7426)

Matthew Van Gundy discovered that NTP incorrectly handled certain crafted broadcast mode packets. A remote attacker could possibly use this issue to perform a denial of service. This issue only affected Ubuntu 14.04 LTS, Ubuntu 16.04 LTS, and Ubuntu 16.10. (CVE-2016-7427, CVE-2016-7428)

Miroslav Lichvar discovered that NTP incorrectly handled certain responses. A remote attacker could possibly use this issue to perform a denial of service. This issue only affected Ubuntu 14.04 LTS, Ubuntu 16.04 LTS, and Ubuntu 16.10. (CVE-2016-7429)

Sharon Goldberg and Aanchal Malhotra discovered that NTP incorrectly handled origin timestamps of zero. A remote attacker could possibly use this issue to bypass the origin timestamp protection mechanism. This issue only affected Ubuntu 16.10. (CVE-2016-7431)

Brian Utterback, Sharon Goldberg and Aanchal Malhotra discovered that NTP incorrectly performed initial sync calculations. This issue only applied to Ubuntu 16.04 LTS and Ubuntu 16.10. (CVE-2016-7433)

Magnus Stubman discovered that NTP incorrectly handled certain mrulist queries. A remote attacker could possibly use this issue to cause NTP to crash, resulting in a denial of service. This issue only affected Ubuntu 16.04 LTS and Ubuntu 16.10. (CVE-2016-7434)

Matthew Van Gund discovered that NTP incorrectly handled origin timestamp checks. A remote attacker could possibly use this issue to perform a denial of service. This issue only affected Ubuntu Ubuntu 16.10, and Ubuntu 17.04. (CVE-2016-9042)

Matthew Van Gundy discovered that NTP incorrectly handled certain control mode packets. A remote attacker could use this issue to set or unset traps. This issue only applied to Ubuntu 14.04 LTS, Ubuntu 16.04 LTS and Ubuntu 16.10. (CVE-2016-9310)

Matthew Van Gundy discovered that NTP incorrectly handled the trap service. A remote attacker could possibly use this issue to cause NTP to crash, resulting in a denial of service. This issue only applied to Ubuntu 14.04 LTS, Ubuntu 16.04 LTS and Ubuntu 16.10. (CVE-2016-9311)

It was discovered that NTP incorrectly handled memory when processing long variables. A remote authenticated user could possibly use this issue to cause NTP to crash, resulting in a denial of service. (CVE-2017-6458)

It was discovered that NTP incorrectly handled memory when processing long variables. A remote authenticated user could possibly use this issue to cause NTP to crash, resulting in a denial of service. This issue only applied to Ubuntu 16.04 LTS, Ubuntu 16.10 and Ubuntu 17.04. (CVE-2017-6460)

It was discovered that the NTP legacy DPTS refclock driver incorrectly handled the /dev/datum device. A local attacker could possibly use this issue to cause a denial of service. (CVE-2017-6462)

It was discovered that NTP incorrectly handled certain invalid settings in a :config directive. A remote authenticated user could possibly use this issue to cause NTP to crash, resulting in a denial of service. (CVE-2017-6463)

It was discovered that NTP incorrectly handled certain invalid mode configuration directives. A remote authenticated user could possibly use this issue to cause NTP to crash, resulting in a denial of service. (CVE-2017-6464)