4.2.8 Release Announcement

Last update: June 28, 2022 21:06 UTC (1f97faf40)

NTF’s NTP Project has been notified of a number of vulnerabilities from Neel Mehta and Stephen Roettger of Google’s Security Team.

The two most serious of these issues and four less serious issues have been resolved as of ntp-4.2.8, which was released on 18 December 2014.

The remaining two issues are addressed by 4.2.8p1, which was released on 4 February 2015.

• 2667: Buffer overflow in crypto_recv() / CVE-2014-9295
• 2668: Buffer overflow in ctl_putdata() / CVE-2014-9295
• 2669: Buffer overflow in configure() / CVE-2014-9295
• 2670: receive(): missing return on error / CVE-2014-9296

These are the vulnerabilities from Neel Mehta and Stephen Roettger of Google’s Security Team:

• We have been generating a weak default key if no authentication key is defined in the ntp.conf file.
• ntp-keygen before 4.2.7p230 used a non-cryptographic random number generator with a weak seed to generate symmetric keys.
• It’s possible to overflow a stack buffer in crypto_recv() when using autokey and potentially allow malicious code to be executed with the privilege level of the ntpd process.
• It’s possible to overflow a buffer in ctl_putdata() and potentially allow malicious code to be executed with the privilege level of the ntpd process.
• It’s possible to overflow a buffer in configure() and potentially allow malicious code to be executed with the privilege level of the ntpd process.
• A missing return; in a rare error condition case in ntp_proto.c:receive() will cause a temporary association to become mobilized. While we haven’t yet found a way this can be exploited, an exploit might be possible.
• In several places, the vallen packet value in ntp_crypto.c is not validated, which can lead to information leakage.
• If ::1 is spoofed on some OSes, the packet is processed instead of being dropped, so ACLs based on IPv6 ::1 addresses can be bypassed. This could allow an attacker to tell your ntpd to, among other things, reconfigure itself.

Additionally, we are working to patch the known deficiencies in NTP’s Autokey protocol, as a stop-gap measure until the Network Time Security draft (which will replace Autokey) is ready to be deployed. These weaknesses were discovered by Dieter Sibold, PhD of PTB, and Stephen Roettger of the Google Security Team.