Package: apache2.2-common Version: 2.2.9-10+lenny3 Severity: normal Tags: patch security
There is a bug in mod_deflate that can lead to a DOS with a very small network traffic. The problem is the following : when downloading a file with mod_deflate enabled and aborting the connexion before the end, mod_deflate will take 100% of a CPU and finish to compress the file for nothing. Even with a not-so-big file (a few dozen of MB), it is possible to "lock" apache by opening simultaneous request on this file and abort the connexion very soon, as the file will be compressed multiple times in parallel, it will make compression times grow and keep the threads busy for a while. The problem arises because mod_deflate doesn't check if the connexion is aborted and goes on whatever happen. The following patch fixes the problem, but at reading the code, I guess that the inflate function is also impacted. Best regards, François --- mod_deflate.c 2008-01-04 15:23:50.000000000 +0100 +++ mod_deflate.c.new 2009-06-26 16:50:36.000000000 +0200 @@ -691,6 +691,10 @@ continue; } + if (r->connection->aborted) { + return APR_ECONNABORTED; + } + /* read */ apr_bucket_read(e, &data, &len, APR_BLOCK_READ); -- Package-specific info: List of enabled modules from 'apache2 -M': alias auth_basic authn_file authz_default authz_groupfile authz_host authz_user autoindex cgi deflate dir env expires headers mime negotiation perl php5 python setenvif status userdir -- System Information: Debian Release: 5.0.1 APT prefers stable APT policy: (990, 'stable') Architecture: i386 (i686) Kernel: Linux 2.6.30 (SMP w/2 CPU cores) Locale: LANG=fr_FR.UTF-8, LC_CTYPE=fr_FR.UTF-8 (charmap=UTF-8) Shell: /bin/sh linked to /bin/bash Versions of packages apache2.2-common depends on: ii apache2-utils 2.2.9-10+lenny3 utility programs for webservers ii libapr1 1.2.12-5 The Apache Portable Runtime Librar ii libaprutil1 1.2.12+dfsg-8+lenny2 The Apache Portable Runtime Utilit ii libc6 2.7-18 GNU C Library: Shared libraries ii libmagic1 4.26-1 File type determination library us ii libssl0.9.8 0.9.8g-15+lenny1 SSL shared libraries ii lsb-base 3.2-20 Linux Standard Base 3.2 init scrip ii mime-support 3.44-1 MIME files 'mime.types' & 'mailcap ii net-tools 1.60-22 The NET-3 networking toolkit ii perl 5.10.0-19 Larry Wall's Practical Extraction ii procps 1:3.2.7-11 /proc file system utilities ii zlib1g 1:1.2.3.3.dfsg-12 compression library - runtime Versions of packages apache2.2-common recommends: ii ssl-cert 1.0.23 simple debconf wrapper for OpenSSL Versions of packages apache2.2-common suggests: ii apache2-doc 2.2.9-10+lenny3 Apache HTTP Server documentation pn apache2-suexec | apache2 <none> (no description available) ii dillo [www-browser] 0.8.6-3 Small and fast web browser ii elinks [www-browser] 0.11.4-3 advanced text-mode WWW browser ii epiphany-gecko [www-brow 2.22.3-9 Intuitive GNOME web browser - Geck ii iceape-browser [www-brow 1.1.14-1 Iceape Navigator (Internet browser ii iceweasel [www-browser] 3.0.6-1 lightweight web browser based on M ii w3m [www-browser] 0.5.2-2+b1 WWW browsable pager with excellent Versions of packages apache2.2-common is related to: pn apache2-mpm-event <none> (no description available) pn apache2-mpm-itk <none> (no description available) ii apache2-mpm-prefork 2.2.9-10+lenny3 Apache HTTP Server - traditional n pn apache2-mpm-worker <none> (no description available) -- no debconf information -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org