Red Hat Bugzilla – Bug 430527
CVE-2004-0492 httpd mod_proxy buffer overflow
Last modified: 2012-06-12 09:43:23 EDT
Common Vulnerabilities and Exposures assigned an identifier CVE-2004-0492 to the following vulnerability:
Heap-based buffer overflow in proxy_util.c for mod_proxy in Apache 1.3.25 to 1.3.31 allows remote attackers to cause a denial of service (process crash) and possibly execute arbitrary code via a negative Content-Length HTTP header field, which causes a large amount of data to be copied.
A security issue has been reported in mod_proxy. See
We have assigned CAN-2004-0492 to this issue.
The flaw affects Apache httpd 1.3.25 to 1.3.31 inclusive that have
mod_proxy enabled and configured. Apache httpd 2.0 is unaffected.
The security issue is a buffer overflow which can be triggered by
getting mod_proxy to connect to a remote server which returns an
invalid (negative) Content-Length. This results in a memcpy to the
heap with a large length value, which will in most cases cause the
Apache child to crash. This does not represent a significant Denial
of Service attack as requests will continue to be handled by other
Apache child processes.
In order to exploit this issue an attacker would need to get an
Apache installation that was configured as a proxy to connect to a
For Red Hat Enterprise Linux we do not believe that this issue can
lead to arbitrary code execution.
A patch to correct this issue is available. See:
This was addressed via:
Red Hat Enterprise Linux version 2.1 (RHSA-2004:245)