RedHat: 'secureweb' mod_ssl Buffer overflow
Posted by Team   
RedHat Linux Updated secureweb packages are now available for Red Hat Secure Web Server3.2 (U.S.). These updates close a buffer overflow in mod_ssl.

                   Red Hat, Inc. Red Hat Security Advisory

Synopsis:          Updated secureweb packages available
Advisory ID:       RHSA-2002:042-12
Issue date:        2002-03-04
Updated on:        2002-03-13
Product:           Red Hat Secure Web Server
Keywords:          mod_ssl buffer overflow session cache
Cross references:  RHSA-2002:041

1. Topic:

Updated secureweb packages are now available for Red Hat Secure Web Server
3.2 (U.S.).  These updates close a buffer overflow in mod_ssl.

2. Relevant releases/architectures:

Red Hat Secure Web Server 3.2 - i386

3. Problem description:

When session caching is enabled, mod_ssl will serialize SSL session
variables to store them for later use. Unpatched versions of mod_ssl prior
to version 2.8.7 using the 'shm' or 'dbm' session caches would do so using
a buffer with a fixed size, making it vulnerable to overflow.

To exploit the overflow, the server must be configured to require client
certificates, and an attacker must obtain a carefully crafted client
certificate that has been signed by a Certificate Authority which is
trusted by the server. If these conditions are met, it is possible for
an attacker to execute arbitrary code on the server.

The Common Vulnerabilities and Exposures project ( has
assigned the name CAN-2002-0082 to this issue.

Pay special attention to the installation instructions in the "Solution"
section below as they differ from standarad upgrade instructions.

4. Solution:

Some of these files are distributed in rhmask format and may only be used
by individuals who have purchased Red Hat Linux 6.2 Professional.

To produce installable RPM files from the rhmask files, retrieve the rhmask
files via ftp and type the following command:

rhmask secureweb-3.2-12.i386.rpm secureweb-3.2.5-1.i386.rpm.rhmask

The original RPM is located only on your Secure Web Server CD, and cannot
be obtained via the Internet. Note: if you do not have the original RPM
located in the same directory as the rhmask file, you will need to prefix
the name of the RPM with the full path name to its location (for example on
your installation CD).

For each RPM for your particular architecture, run:

rpm -Fvh [filename]

where [filename] is the name of the RPM package.

To restart your Secure Web Server, type the following command in a shell
prompt as root:

/etc/rc.d/init.d/httpsd restart

5. Bug IDs fixed  (http://bugzilla.Red for more info):

6. RPMs required:

Red Hat Secure Web Server 3.2:



7. Verification:

MD5 sum                          Package Name
df95f1339f71af47d70ca965a9fe11cc 3.2/other_prod/secureweb/SRPMS/secureweb-3.2.5-3.nosrc.rpm
de9d5943625415a7492a2f5ad1165f37 3.2/other_prod/secureweb/i386/secureweb-3.2.5-3.i386.rpm.rhmask
1b39d3833a18b2c2b4b30f8d5ed88283 3.2/other_prod/secureweb/i386/secureweb-devel-3.2.5-3.i386.rpm
3ce2a02339fe3caf436a9eb2e1154f70 3.2/other_prod/secureweb/i386/secureweb-manual-3.2.5-3.i386.rpm

These packages are GPG signed by Red Hat, Inc. for security.  Our key
is available at:

You can verify each package with the following command:
    rpm --checksig  

If you only wish to verify that each package has not been corrupted or
tampered with, examine only the md5sum with the following command:
    rpm --checksig --nogpg 

8. References:

Copyright(c) 2000, 2001, 2002 Red Hat, Inc.