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FreeBSD Security
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Crypto-NAK packets can be used to cause ntpd(8) to accept time from an unauthenticated ephemeral symmetric peer by bypassing the authentication required to mobilize peer associations. [CVE-2015-7871] FreeBSD 9.3 and 10.1 are not affected.
If ntpd(8) is fed a crafted mode 6 or mode 7 packet containing an unusual long data value where a network address is expected, the decodenetnum() function will abort with an assertion failure instead of simply returning a failure condition. [CVE-2015-7855]
If ntpd(8) is configured to allow remote configuration, and if the (possibly spoofed) source IP address is allowed to send remote configuration requests, and if the attacker knows the remote configuration password or if ntpd(8) was configured to disable authentication, then an attacker can send a set of packets to ntpd(8) that may cause it to crash, with the hypothetical possibility of a small code injection. [CVE-2015-7854]
A negative value for the datalen parameter will overflow a data buffer. NTF's ntpd(8) driver implementations always set this value to 0 and are therefore not vulnerable to this weakness. If you are running a custom refclock driver in ntpd(8) and that driver supplies a negative value for datalen (no custom driver of even minimal competence would do this) then ntpd would overflow a data buffer. It is even hypothetically possible in this case that instead of simply crashing ntpd the attacker could effect a code injection attack. [CVE-2015-7853]
If an attacker can figure out the precise moment that ntpq(8) is listening for data and the port number it is listening on or if the attacker can provide a malicious instance ntpd(8) that victims will connect to then an attacker can send a set of crafted mode 6 response packets that, if received by ntpq(8), can cause ntpq(8) to crash. [CVE-2015-7852]
If ntpd(8) is configured to allow remote configuration, and if the (possibly spoofed) IP address is allowed to send remote configuration requests, and if the attacker knows the remote configuration password or if ntpd(8) was configured to disable authentication, then an attacker can send a set of packets to ntpd that may cause ntpd(8) to overwrite files. [CVE-2015-7851]. The default configuration of ntpd(8) within FreeBSD does not allow remote configuration.
If ntpd(8) is configured to allow remote configuration, and if the (possibly spoofed) source IP address is allowed to send remote configuration requests, and if the attacker knows the remote configuration password or if ntpd(8) was configured to disable authentication, then an attacker can send a set of packets to ntpd that will cause it to crash and/or create a potentially huge log file. Specifically, the attacker could enable extended logging, point the key file at the log file, and cause what amounts to an infinite loop. [CVE-2015-7850]. The default configuration of ntpd(8)
within FreeBSD does not allow remote configuration.
If ntpd(8) is configured to allow remote configuration, and if the (possibly spoofed) source IP address is allowed to send remote configuration requests, and if the attacker knows the remote configuration password or if ntpd was configured to disable authentication, then an attacker can send a set of packets to ntpd that may cause a crash or theoretically perform a code injection attack. [CVE-2015-7849]. The default configuration of ntpd(8) within FreeBSD does not allow remote configuration.
If ntpd(8) is configured to enable mode 7 packets, and if the use of mode 7 packets is not properly protected thru the use of the available mode 7 authentication and restriction mechanisms, and if the (possibly spoofed) source IP address is allowed to send mode 7 queries, then an attacker can send a crafted packet to ntpd that will cause it to crash. [CVE-2015-7848]. The default configuration of ntpd(8) within FreeBSD does not allow mode 7 packets.
If ntpd(8) is configured to use autokey, then an attacker can send packets to ntpd that will, after several days of ongoing attack, cause it to run out of memory. [CVE-2015-7701]. The default configuration of ntpd(8) within FreeBSD does not use autokey.
If ntpd(8) is configured to allow for remote configuration, and if the (possibly spoofed) source IP address is allowed to send remote configuration requests, and if the attacker knows the remote configuration password, it's possible for an attacker to use the "pidfile" or "driftfile" directives to potentially overwrite other files. [CVE-2015-5196]. The default configuration of ntpd(8) within FreeBSD does not allow remote configuration
An ntpd(8) client that honors Kiss-of-Death responses will honor KoD messages that have been forged by an attacker, causing it to delay or stop querying its servers for time updates. Also, an attacker can forge packets that claim to be from the target and send them to servers often enough that a server that implements KoD rate limiting will send the target machine a KoD response to attempt to reduce the rate of incoming packets, or it may also trigger a firewall block at the server for packets from the target machine. For either of these attacks to succeed, the attacker must know what servers the target is communicating with. An attacker can be anywhere on the Internet and can frequently learn the identity of the target's time source by sending the target a time query. [CVE-2015-7704]
The fix for CVE-2014-9750 was incomplete in that there were certain code paths where a packet with particular autokey operations that contained malicious data was not always being completely validated. Receipt of these packets can cause ntpd to crash. [CVE-2015-7702]. The default configuration of ntpd(8) within FreeBSD does not use autokey.
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