RHEL 4 / 5 : ntp (RHSA-2009:1648)

Medium Nessus Plugin ID 43080


The remote Red Hat host is missing a security update.


An updated ntp package that fixes a security issue is now available for Red Hat Enterprise Linux 4 and 5.

This update has been rated as having moderate security impact by the Red Hat Security Response Team.

The Network Time Protocol (NTP) is used to synchronize a computer's time with a referenced time source.

Robin Park and Dmitri Vinokurov discovered a flaw in the way ntpd handled certain malformed NTP packets. ntpd logged information about all such packets and replied with an NTP packet that was treated as malformed when received by another ntpd. A remote attacker could use this flaw to create an NTP packet reply loop between two ntpd servers via a malformed packet with a spoofed source IP address and port, causing ntpd on those servers to use excessive amounts of CPU time and fill disk space with log messages. (CVE-2009-3563)

All ntp users are advised to upgrade to this updated package, which contains a backported patch to resolve this issue. After installing the update, the ntpd daemon will restart automatically.


Update the affected ntp package.

See Also



Plugin Details

Severity: Medium

ID: 43080

File Name: redhat-RHSA-2009-1648.nasl

Version: $Revision: 1.18 $

Type: local

Agent: unix

Published: 2009/12/09

Modified: 2017/01/03

Dependencies: 12634

Risk Information

Risk Factor: Medium


Base Score: 6.4

Temporal Score: 5.3

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:P

Temporal Vector: CVSS2#E:F/RL:OF/RC:ND

Vulnerability Information

CPE: p-cpe:/a:redhat:enterprise_linux:ntp, cpe:/o:redhat:enterprise_linux:4, cpe:/o:redhat:enterprise_linux:4.8, cpe:/o:redhat:enterprise_linux:5, cpe:/o:redhat:enterprise_linux:5.4

Required KB Items: Host/local_checks_enabled, Host/RedHat/release, Host/RedHat/rpm-list, Host/cpu

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 2009/12/08

Reference Information

CVE: CVE-2009-3563

OSVDB: 60847

RHSA: 2009:1648