USN-177-1: Apache 2 vulnerabilities

07 September 2005

Apache 2 vulnerabilities

Releases

Details

Apache did not honour the "SSLVerifyClient require" directive within a

block if the surrounding block contained a
directive "SSLVerifyClient optional". This allowed clients to bypass
client certificate validation on servers with the above configuration.
(CAN-2005-2700)

Filip Sneppe discovered a Denial of Service vulnerability in the byte
range filter handler. By requesting certain large byte ranges, a
remote attacker could cause memory exhaustion in the server.
(CAN-2005-2728)

The updated libapache-mod-ssl also fixes two older Denial of Service
vulnerabilities: A format string error in the ssl_log() function which
could be exploited to crash the server (CAN-2004-0700), and a flaw in
the SSL cipher negotiation which could be exploited to terminate a
session (CAN-2004-0885). Please note that Apache 1.3 and
libapache-mod-ssl are not officially supported (they are in the
"universe" component of the Ubuntu archive).

Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 5.04
  • apache2-mpm-worker -
  • apache2-mpm-perchild -
  • apache2-mpm-prefork -
  • apache2-mpm-threadpool -
  • libapache-mod-ssl -
Ubuntu 4.10
  • apache2-mpm-worker -
  • apache2-mpm-perchild -
  • apache2-mpm-prefork -
  • apache2-mpm-threadpool -
  • libapache-mod-ssl -

In general, a standard system update will make all the necessary changes.