----------------------------------------------------------------------

SC World Congress, New York, USA, 16 November 2011
Visit the Secunia booth (#203) and discover how you can improve your handling of third party programs:

http://secunia.com/resources/events/sc_2011/ 

----------------------------------------------------------------------

TITLE:
Apache HTTP Server "ap_pregsub()" Denial of Service Vulnerability

SECUNIA ADVISORY ID:
SA46823

VERIFY ADVISORY:
Secunia.com
http://secunia.com/advisories/46823/
Customer Area (Credentials Required)
https://ca.secunia.com/?page=viewadvisory&vuln_id=46823

RELEASE DATE:
2011-11-11

DISCUSS ADVISORY:
http://secunia.com/advisories/46823/#comments

AVAILABLE ON SITE AND IN CUSTOMER AREA:
 * Last Update
 * Popularity
 * Comments
 * Criticality Level
 * Impact
 * Where
 * Solution Status
 * Operating System / Software
 * CVE Reference(s)

http://secunia.com/advisories/46823/

ONLY AVAILABLE IN CUSTOMER AREA:
 * Authentication Level
 * Report Reliability
 * Secunia PoC
 * Secunia Analysis
 * Systems Affected
 * Approve Distribution
 * Remediation Status
 * Secunia CVSS Score
 * CVSS

https://ca.secunia.com/?page=viewadvisory&vuln_id=46823

ONLY AVAILABLE WITH SECUNIA CSI AND SECUNIA PSI:
 * AUTOMATED SCANNING

http://secunia.com/vulnerability_scanning/personal/
http://secunia.com/vulnerability_scanning/corporate/wsus_sccm_3rd_third_party_patching/

DESCRIPTION:
halfdog has reported a vulnerability in Apache HTTP Server, which can
be exploited by malicious, local users to cause a DoS (Denial of
Service).

The vulnerability is caused due to the "apr_pregsub()" function
(server/utils.c) not properly limiting the maximum size of
environment variable values, which can be exploited to e.g. cause a
huge memory consumption via a specially crafted ".htaccess" file.

This is related to:
SA45793

The vulnerability is reported in versions 2.0.64 and 2.2.21. Other
versions may also be affected.

SOLUTION:
Restrict access to trusted users only.

PROVIDED AND/OR DISCOVERED BY:
halfdog

ORIGINAL ADVISORY:
http://www.halfdog.net/Security/2011/ApacheModSetEnvIfIntegerOverflow/
http://www.halfdog.net/Security/2011/ApacheModSetEnvIfIntegerOverflow/DemoExploit.html

OTHER REFERENCES:
Further details available in Customer Area:
http://secunia.com/vulnerability_intelligence/

DEEP LINKS:
Further details available in Customer Area:
http://secunia.com/vulnerability_intelligence/

EXTENDED DESCRIPTION:
Further details available in Customer Area:
http://secunia.com/vulnerability_intelligence/

EXTENDED SOLUTION:
Further details available in Customer Area:
http://secunia.com/vulnerability_intelligence/

EXPLOIT:
Further details available in Customer Area:
http://secunia.com/vulnerability_intelligence/

----------------------------------------------------------------------

About:
This Advisory was delivered by Secunia as a free service to help
private users keeping their systems up to date against the latest
vulnerabilities.

Subscribe:
http://secunia.com/advisories/secunia_security_advisories/

Definitions: (Criticality, Where etc.)
http://secunia.com/advisories/about_secunia_advisories/


Please Note:
Secunia recommends that you verify all advisories you receive by
clicking the link.
Secunia NEVER sends attached files with advisories.
Secunia does not advise people to install third party patches, only
use those supplied by the vendor.

----------------------------------------------------------------------

Unsubscribe: Secunia Security Advisories
http://secunia.com/sec_adv_unsubscribe/?email=packet%40packetstormsecurity.org

----------------------------------------------------------------------