Vulnerabilities (CVE)

An integer overflow can occur in NTP-dev.4.3.70 leading to an out-of-bounds memory copy operation when processing a specially crafted private mode packet. The crafted packet needs to have the correct message authentication code and a valid timestamp. When processed by the NTP daemon, it leads to an immediate crash.

ntpd in ntp before 4.2.8p14 and 4.3.x before 4.3.100 allows remote attackers to cause a denial of service (daemon exit or system time change) by predicting transmit timestamps for use in spoofed packets. The victim must be relying on unauthenticated IPv4 time sources. There must be an off-path attacker who can query time from the victim's ntpd instance.

ntpd in ntp before 4.2.8p14 and 4.3.x before 4.3.100 allows an off-path attacker to block unauthenticated synchronization via a server mode packet with a spoofed source IP address, because transmissions are rescheduled even when a packet lacks a valid origin timestamp.

NTP before 4.2.8p10 and 4.3.x before 4.3.94 allows remote attackers to cause a denial of service (ntpd crash) via a malformed mode configuration directive.

NTP before 4.2.8p9 does not properly perform the initial sync calculations, which allows remote attackers to unspecified impact via unknown vectors, related to a "root distance that did not include the peer dispersion."

The getresponse function in ntpq in NTP versions before 4.2.8p9 and 4.3.x before 4.3.90 allows remote attackers to cause a denial of service (infinite loop) via crafted packets with incorrect values.

The mx4200_send function in the legacy MX4200 refclock in NTP before 4.2.8p10 and 4.3.x before 4.3.94 does not properly handle the return value of the snprintf function, which allows local users to execute arbitrary code via unspecified vectors, which trigger an out-of-bounds memory write.

NTP before 4.2.8p7 and 4.3.x before 4.3.92 allows remote attackers to cause a denial of service (prevent subsequent authentication) by leveraging knowledge of the controlkey or requestkey and sending a crafted packet to ntpd, which changes the value of trustedkey, controlkey, or requestkey. NOTE: this vulnerability exists because of a CVE-2016-2516 regression.

ntpd in NTP 4.2.8p3 and NTPsec a5fb34b9cc89b92a8fef2f459004865c93bb7f92 relies on the underlying operating system to protect it from requests that impersonate reference clocks. Because reference clocks are treated like other peers and stored in the same structure, any packet with a source ip address of a reference clock (127.127.1.1 for example) that reaches the receive() function will match that reference clock's peer record and will be treated as a trusted peer. Any system that lacks the typic ... ntpd in NTP 4.2.8p3 and NTPsec a5fb34b9cc89b92a8fef2f459004865c93bb7f92 relies on the underlying operating system to protect it from requests that impersonate reference clocks. Because reference clocks are treated like other peers and stored in the same structure, any packet with a source ip address of a reference clock (127.127.1.1 for example) that reaches the receive() function will match that reference clock's peer record and will be treated as a trusted peer. Any system that lacks the typical martian packet filtering which would block these packets is in danger of having its time controlled by an attacker.

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NTP before 4.2.8p6 and 4.3.x before 4.3.90 allows remote attackers to bypass the origin timestamp validation via a packet with an origin timestamp set to zero.

The "pidfile" or "driftfile" directives in NTP ntpd 4.2.x before 4.2.8p4, and 4.3.x before 4.3.77, when ntpd is configured to allow remote configuration, allows remote attackers with an IP address that is allowed to send configuration requests, and with knowledge of the remote configuration password to write to arbitrary files via the :config command.

Memory leak in the CRYPTO_ASSOC function in ntpd in NTP 4.2.x before 4.2.8p4, and 4.3.x before 4.3.77 allows remote attackers to cause a denial of service (memory consumption).

The crypto_xmit function in ntpd in NTP 4.2.x before 4.2.8p4, and 4.3.x before 4.3.77 allows remote attackers to cause a denial of service (crash). NOTE: This vulnerability exists due to an incomplete fix for CVE-2014-9750.

NTP before 4.2.8p9 allows remote attackers to bypass the origin timestamp protection mechanism via an origin timestamp of zero. NOTE: this vulnerability exists because of a CVE-2015-8138 regression.

The broadcast mode replay prevention functionality in ntpd in NTP before 4.2.8p9 allows remote attackers to cause a denial of service (reject broadcast mode packets) via a crafted broadcast mode packet.

The read_mru_list function in NTP before 4.2.8p9 allows remote attackers to cause a denial of service (crash) via a crafted mrulist query.

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.

ntp-keygen in ntp 4.2.8px before 4.2.8p2-RC2 and 4.3.x before 4.3.12 does not generate MD5 keys with sufficient entropy on big endian machines when the lowest order byte of the temp variable is between 0x20 and 0x7f and not #, which might allow remote attackers to obtain the value of generated MD5 keys via a brute force attack with the 93 possible keys.

ntpd in ntp before 4.2.8p3 with remote configuration enabled allows remote authenticated users with knowledge of the configuration password and access to a computer entrusted to perform remote configuration to cause a denial of service (service crash) via a NULL byte in a crafted configuration directive packet.

The Windows installer for NTP before 4.2.8p10 and 4.3.x before 4.3.94 allows local users to have unspecified impact via vectors related to an argument with multiple null bytes.

ntp_openssl.m4 in ntpd in NTP before 4.2.7p112 allows remote attackers to cause a denial of service (segmentation fault) via a crafted statistics or filegen configuration command that is not enabled during compilation.

A malicious authenticated peer can create arbitrarily-many ephemeral associations in order to win the clock selection algorithm in ntpd in NTP 4.2.8p4 and earlier and NTPsec 3e160db8dc248a0bcb053b56a80167dc742d2b74 and a5fb34b9cc89b92a8fef2f459004865c93bb7f92 and modify a victim's clock.

The MATCH_ASSOC function in NTP before version 4.2.8p9 and 4.3.x before 4.3.92 allows remote attackers to cause an out-of-bounds reference via an addpeer request with a large hmode value.

An attacker can spoof a packet from a legitimate ntpd server with an origin timestamp that matches the peer->dst timestamp recorded for that server. After making this switch, the client in NTP 4.2.8p4 and earlier and NTPSec aa48d001683e5b791a743ec9c575aaf7d867a2b0c will reject all future legitimate server responses. It is possible to force the victim client to move time after the mode has been changed. ntpq gives no indication that the mode has been switched.

The ULOGTOD function in ntp.d in SNTP before 4.2.7p366 does not properly perform type conversions from a precision value to a double, which allows remote attackers to cause a denial of service (infinite loop) via a crafted NTP packet.

The ntpq saveconfig command in NTP 4.1.2, 4.2.x before 4.2.8p6, 4.3, 4.3.25, 4.3.70, and 4.3.77 does not properly filter special characters, which allows attackers to cause unspecified impact via a crafted filename.

ntpd in NTP before 4.2.8p6 and 4.3.x before 4.3.90 allows remote attackers to cause a denial of service (NULL pointer dereference) via a ntpdc reslist command.

The ntpq protocol in NTP before 4.2.8p7 allows remote attackers to conduct replay attacks by sniffing the network.

ntpd in NTP 4.2.x before 4.2.8p4, and 4.3.x before 4.3.77 allows remote authenticated users to cause a denial of service (infinite loop or crash) by pointing the key file at the log file.

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.

Use-after-free vulnerability in ntpd in NTP 4.2.x before 4.2.8p4, and 4.3.x before 4.3.77 allows remote authenticated users to possibly execute arbitrary code or cause a denial of service (crash) via crafted packets.

Buffer overflow in the legacy Datum Programmable Time Server (DPTS) refclock driver in NTP before 4.2.8p10 and 4.3.x before 4.3.94 allows local users to have unspecified impact via a crafted /dev/datum device.

ntpd in NTP before 4.2.8p9 allows remote attackers to cause a denial of service (reject broadcast mode packets) via the poll interval in a broadcast packet.

ntpq in NTP before 4.2.8p7 allows remote attackers to obtain origin timestamps and then impersonate peers via unspecified vectors.

The crypto_xmit function in ntpd in NTP 4.2.x before 4.2.8p4, and 4.3.x before 4.3.77 allows remote attackers to cause a denial of service (crash). NOTE: This vulnerability exists due to an incomplete fix for CVE-2014-9750.

The datalen parameter in the refclock driver in NTP 4.2.x before 4.2.8p4, and 4.3.x before 4.3.77 allows remote attackers to execute arbitrary code or cause a denial of service (crash) via a negative input value.

ntpd in NTP before 4.2.8p9, when running on Windows, allows remote attackers to cause a denial of service via a large UDP packet.

The control mode (mode 6) functionality in ntpd in NTP before 4.2.8p9 allows remote attackers to set or unset traps via a crafted control mode packet.

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.

The decodenetnum function in ntpd in NTP 4.2.x before 4.2.8p4, and 4.3.x before 4.3.77 allows remote attackers to cause a denial of service (assertion failure) via a 6 or mode 7 packet containing a long data value.