Apache 2.0.46 Released – Security and Bugfix Release

The Apache Software Foundation and the Apache HTTP Server Project are pleased to announce the ninth public release of the Apache 2.0 HTTP Server. This Announcement notes the significant changes in 2.0.46 as compared to 2.0.45.

This version of Apache is principally a security and bug fix release. A summary of the bug fixes is given at the end of this document. Of particular note is that 2.0.46 addresses two security vulnerabilities:

Apache 2.0 versions 2.0.37 through 2.0.45 can be caused to crash in certain circumstances. This can be triggered remotely through mod_dav and possibly other mechanisms. The crash was originally reported by David Endler and was researched and fixed by Joe Orton . Specific details and an analysis of the crash will be published Friday, May 30. No more specific information is disclosed at this time, but all Apache 2.0 users are encouraged to upgrade now.

Apache 2.0 versions 2.0.40 through 2.0.45 on Unix platforms were vulnerable to a denial-of-service attack on the basic authentication module, which was reported by John Hughes . A bug in the configuration scripts caused the apr_password_validate() function to be thread-unsafe on platforms with crypt_r(), including AIX and Linux. All versions of Apache 2.0 have this thread-safety problem on platforms with no crypt_r() and no thread-safe crypt(), such as Mac OS X and possibly others. When using a threaded MPM (which is not the default on these platforms), this allows remote attackers to create a denial of service which causes valid usernames and passwords for Basic Authentication to fail until Apache is restarted. We do not believe this bug could allow unauthorized users to gain access to protected resources.

The Apache Software Foundation would like to thank David Endler and John Hughes for the responsible reporting of these issues.

This release is compatible with modules compiled for 2.0.42 and later versions. We consider this release to be the best version of Apache available and encourage users of all prior versions to upgrade.

Apache 2.0.46 is available for download from


Please see the CHANGES_2.0 file, linked from the above page, for a full list of changes.

Apache 2.0 offers numerous enhancements, improvements, and performance boosts over the 1.3 codebase. For an overview of new features introduced after 1.3 please see


When upgrading or installing this version of Apache, please keep in mind the following:

If you intend to use Apache with one of the threaded MPMs, you must ensure that the modules (and the libraries they depend on) that you will be using are thread-safe. Please contact the vendors of these modules to obtain this information.

Apache 2.0.46 Major changes

Security vulnerabilities closed since Apache 2.0.45

*) SECURITY [CAN-2003-0245]: Fixed a bug that could be triggered remotely through mod_dav and possibly other mechanisms, causing an Apache child process to crash. The crash was first reported by David Endler and was researched and fixed by Joe Orton . Details will be released on 30 May 2003.

*) SECURITY [CAN-2003-0189]: Fixed a denial-of-service vulnerability affecting basic authentication on Unix platforms related to thread-safety in apr_password_validate(). The problem was reported by John Hughes.

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