The latest version of Apache, 2.0.46 was described as "principally a security and bug fix release" in a bulletin released by the open-source organisation.
Among those fixes is a patch for a security hole in the mod_dav module that could be exploited remotely, causing an Apache web server process to crash.
Mod_dav is an open-source module that provides WebDAV (World Wide Web Distributed Authoring and Versioning) protocol support for the Apache Web server.
WebDAV is a set of extensions to HTTP (Hypertext Transfer Protocol) which allows users to edit and manage files on remote web servers. The protocol is designed to create interoperable, collaborative applications that facilitate geographically dispersed "virtual" software development teams.
Few details were available regarding the mod_dav vulnerability, which was first discovered and reported to the Foundation by a researcher at security firm iDefense.
In March, Microsoft released a patch for a security hole in a core Windows component used to handle an unchecked buffer in a Windows 2000 component used to handle the WebDAV protocol.
That flaw, which has already been exploited by hackers, could enable an attacker to cause a buffer overflow on the machine running Internet Information Server, according to Microsoft Security bulletin MS03-007.
A second fix is for a denial-of-service vulnerability affecting Apache's authentication module.
By exploiting a bug in configuration scripts used by a function for password validation, attackers could launch remote denial-of-service attacks that would cause valid user names and passwords to be rejected, the bulletin said.
The vulnerabilities affect versions of Apache ranging from 2.0.37 up to the most recent release, 2.0.45, which came out in April.
That latest version was also released in response to a previously unknown critical security flaw which, like the mod_dav vulnerability, was discovered by iDefense.
As with its last software update, the Apache Software Foundation said that 2.0.46 was the "best version of Apache available" and recommended that users of previous Apache versions should upgrade.
Paul Roberts writes for IDG News Service