[ GLSA 201001-01 ] NTP: Denial of Service

[GLSA]

Gentoo Linux Security Advisory

Title: NTP: Denial of Service (GLSA 201001-01)
Severity: normal
Exploitable: remote
Date: January 03, 2010
Bug(s): #290881
ID: 201001-01

Synopsis


A Denial of Service condition in ntpd can cause excessive CPU or bandwidth
consumption.


Background


NTP is a set of the Network Time Protocol programs.


Affected Packages

Package: net-misc/ntp
Vulnerable: < 4.2.4_p7-r1
Unaffected: >= 4.2.4_p7-r1
Architectures: All supported architectures


Description


Robin Park and Dmitri Vinokurov discovered that ntp_request.c in ntpd
does not handle MODE_PRIVATE packets correctly, causing a continuous
exchange of MODE_PRIVATE error responses between two NTP daemons or
causing high CPU load on a single host.


Impact


A remote, unauthenticated attacker could send a specially crafted
MODE_PRIVATE packet, allowing for a Denial of Service condition (CPU
and bandwidth consumption).


Workaround


There is no known workaround at this time.


Resolution


All NTP users should upgrade to the latest version: