Multiple buffer overflows in the ctl_put* functions in NTP before 4.2.8p10 and 4.3.x before 4.3.94 allow remote authenticated users to have unspecified impact via a long variable.

NTP before 4.2.8p10 and 4.3.x before 4.3.94, when using PPSAPI, allows local users to gain privileges via a DLL in the PPSAPI_DLLS environment variable.

Stack-based buffer overflow in 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 an application path on the command line.

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.

ntpd in NTP before 4.2.8p7 and 4.3.x before 4.3.92 allows remote attackers to cause a denial of service (ntpd abort) by a large request data value, which triggers the ctl_getitem function to return a NULL value.

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.

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.

NTP before 4.2.8p7 and 4.3.x before 4.3.92, when mode7 is enabled, allows remote attackers to cause a denial of service (ntpd abort) by using the same IP address multiple times in an unconfig directive.

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

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

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.

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.

NTP before 4.2.8p6 and 4.3.0 before 4.3.90 allows a remote attackers to cause a denial of service (stack exhaustion) via an ntpdc relist command, which triggers recursive traversal of the restriction list.

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 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.

The nextvar function in NTP before 4.2.8p6 and 4.3.x before 4.3.90 does not properly validate the length of its input, which allows an attacker to cause a denial of service (application crash).

NTP before 4.2.8p6 and 4.3.x before 4.3.90, when configured in broadcast mode, allows man-in-the-middle attackers to conduct replay attacks by sniffing the network.

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.

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.