Hi, * Nico Golde <nion@debian.org> [2009-12-08 20:19]: > -------------------------------------------------------------------------- > Debian Security Advisory DSA-1908-1 security@debian.org > http://www.debian.org/security/ Nico Golde > December 8th, 2009 http://www.debian.org/security/faq > -------------------------------------------------------------------------- > > Package : ntp > Vulnerability : denial of service > Problem type : remote > Debian-specific: no > Debian bug : 560074 > CVE ID : CVE-2009-3563 > > Robin Park and Dmitri Vinokurov discovered that the daemon component of > the ntp package, a reference implementation of the NTP protocol, is > not properly reacting to certain incoming packets. > > An unexpected NTP mode 7 packets (MODE_PRIVATE) with spoofed IP data can lead > ntpd to reply with a mode 7 response to the spoofed address. This may result > in the service playing packet ping-pong with other ntp servers or even itself > which causes CPU usage and excessive disk use due to logging. An attacker > can use this to conduct denial of service attacks. [...] JFYI, you can use "restrict ... noquery" or "restrict ... ignore" in your ntp.conf file to limit the source addresses to which ntpd will respond to workaround that bug as well. Cheers Nico -- Nico Golde - http://www.ngolde.de - nion@jabber.ccc.de - GPG: 0xA0A0AAAA For security reasons, all text in this mail is double-rot13 encrypted.
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