RHSA-2015:0104: ntp security update

Description

The Network Time Protocol (NTP) is used to synchronize a computer's timewith a referenced time source.Multiple buffer overflow flaws were discovered in ntpd's crypto_recv(),ctl_putdata(), and configure() functions. A remote attacker could useeither of these flaws to send a specially crafted request packet that couldcrash ntpd or, potentially, execute arbitrary code with the privileges ofthe ntp user. Note: the crypto_recv() flaw requires non-defaultconfigurations to be active, while the ctl_putdata() flaw, by default, canonly be exploited via local attackers, and the configure() flaw requiresadditional authentication to exploit. (CVE-2014-9295)It was found that ntpd automatically generated weak keys for its internaluse if no ntpdc request authentication key was specified in the ntp.confconfiguration file. A remote attacker able to match the configured IPrestrictions could guess the generated key, and possibly use it to sendntpdc query or configuration requests. (CVE-2014-9293)It was found that ntp-keygen used a weak method for generating MD5 keys.This could possibly allow an attacker to guess generated MD5 keys thatcould then be used to spoof an NTP client or server. Note: it isrecommended to regenerate any MD5 keys that had explicitly been generatedwith ntp-keygen; the default installation does not contain such keys.(CVE-2014-9294)A missing return statement in the receive() function could potentiallyallow a remote attacker to bypass NTP's authentication mechanism.(CVE-2014-9296)All ntp users are advised to upgrade to this updated package, whichcontains backported patches to resolve these issues. After installing theupdate, the ntpd daemon will restart automatically.