Vulnerability Note VU#132110

Apache HTTP Server vulnerable to DoS race condition in the handling of short-lived connections

Overview

A race condition exists in Apache 2 HTTP Server that may cause a denial-of-service condition on some platforms.

I. Description

Apache HTTP Server versions 2.0.48 and prior contain a race condition in the handling of short-lived connections. According to the Apache anouncement, when using multiple listening sockets, a short-lived connection on a rarely-used socket may cause the child process to hold the accept mutex, blocking new connections from being served until another connection uses the socket.

This vulnerability does not affect Apache 2.x servers running on FreeBSD or Linux.

II. Impact

A denial-of-service situation may occur due the race condition until another connection is made the the socket.

III. Solution

This problem is resolved in Apache HTTP Server 2.0.49.

Systems Affected

Vendor	Status	Date Notified	Date Updated
Apache Software Foundation	Vulnerable	24-Mar-2004
Sun Microsystems Inc.	Vulnerable	25-Aug-2004

References

http://www.apache.org/dist/httpd/Announcement2.html
http://secunia.com/advisories/11170/

Credit

Thanks to Apache Software Foundation for reporting this vulnerability.

This document was written by Jason A Rafail.

Other Information

Date Public:	2004-03-19
Date First Published:	2004-03-24
Date Last Updated:	2004-08-25
CERT Advisory:
CVE-ID(s):	CAN-2004-0174
NVD-ID(s):	CAN-2004-0174
US-CERT Technical Alerts:
Metric:	3.37
Document Revision:	3

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