eEye Digital Security eEye Digital Security
  • Login to the eEye Business Client Portal
  • Shop for eEye Products
  • Read the eEye Blog
  • Subscribe to eEye RSS Feeds
  • Follow eEye on Twitter
  • Follow eEye of Facebook

Research > Zero-Day Tracker > 20111102

Apache HTTP Server ap_pregsub() buffer overflow

Date Disclosed:

Date Patched:

Apache Software Foundation

Affected Software:
Apache HTTP Server 2.2.21 and earlier

There is an integer overflow vulnerability in the ap_pregsub function of the Apache Web server.  This integer overflow can lead to a buffer overflow and allow an attacker to execute arbitrary code.  The Apache Web server runs with elevated privileges, an attacker would need to exploit this locally but would gain elevated privileges on the machine.


Code Execution:

Local Elevation of Privilege to root privileges
This local vulnerability allows an attacker with file write privileges to run arbitrary code under the context of the Apache Server.

Disable the use of ".htaccess" on all locations that are writable by normal users.


BeyondTrust's Retina® Network Security Scanner scans devices to detect for this vulnerability.
  •  15584 - Apache Mod_SetEnvIf .htaccess Privilege Escalation


11.02.2011 - Public Information Released
1.31.2012 - Apache releases HTTP Server 2.2.22, which contains a fix for CVE-2011-3607

Copyright ©1998-2011 eEye Digital Security
Permission is hereby granted for the redistribution of this alert electronically. It is not to be edited in any way without express consent of eEye. If you wish to reprint the whole or any part of this alert in any other medium excluding electronic medium, please email for permission.

The information within this paper may change without notice. Use of this information constitutes acceptance for use in an AS IS condition. There are no warranties, implied or express, with regard to this information. In no event shall the author be liable for any direct or indirect damages whatsoever arising out of or in connection with the use or spread of this information. Any use of this information is at the user's own risk.

Next Steps

Free Trial
Test drive an eEye product
On-demand Demo
See an online product tour
One-on-one Demo
Schedule a personalized tour
Compare Products
See side-by-side features
Buy Now
Go to eEye product store
Contact | Site Map | Privacy | Website Feedback | 1.866.339.3732
© 1998 – 2012 eEye Digital Security. All rights reserved.