RHSA-2009:1648: Moderate: ntp security update
The Network Time Protocol (NTP) is used to synchronize a computer's timewith a referenced time source.Robin Park and Dmitri Vinokurov discovered a flaw in the way ntpd handledcertain malformed NTP packets. ntpd logged information about all suchpackets and replied with an NTP packet that was treated as malformed whenreceived by another ntpd. A remote attacker could use this flaw to createan NTP packet reply loop between two ntpd servers via a malformed packetwith a spoofed source IP address and port, causing ntpd on those servers touse 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, whichcontains a backported patch to resolve this issue. After installing theupdate, the ntpd daemon will restart automatically.
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of RHSA-2009:1648?
The severity of RHSA-2009:1648 is classified as moderate.
How do I fix RHSA-2009:1648?
To fix RHSA-2009:1648, you should update the ntp package to versions 4.2.2p1-9.el5_4.1 or 4.2.0.a.20040617-8.el4_8.1 depending on your system.
What systems are affected by RHSA-2009:1648?
The affected systems include those running the ntp package prior to the specified update versions.
What was the cause of the vulnerability in RHSA-2009:1648?
The vulnerability in RHSA-2009:1648 was caused by a flaw in how ntpd handled certain malformed NTP packets.
Is there a workaround for RHSA-2009:1648?
There is no specific workaround for RHSA-2009:1648; updating the software is recommended to mitigate the vulnerability.