Public Date:
750935: CVE-2011-4415 httpd: SetEnvIf resource exhaustion

The MITRE CVE dictionary describes this issue as:

The ap_pregsub function in server/util.c in the Apache HTTP Server 2.0.x through 2.0.64 and 2.2.x through 2.2.21, when the mod_setenvif module is enabled, does not restrict the size of values of environment variables, which allows local users to cause a denial of service (memory consumption or NULL pointer dereference) via a .htaccess file with a crafted SetEnvIf directive, in conjunction with a crafted HTTP request header, related to (1) the "len +=" statement and (2) the apr_pcalloc function call, a different vulnerability than CVE-2011-3607.

Find out more about CVE-2011-4415 from the MITRE CVE dictionary dictionary and NIST NVD.


The ASF Security Team does not consider resource exhaustion caused by .htaccess files to be a security defect. The Red Hat Security Response Team agrees with their assessment and so does not consider this to be a security flaw.

CVSS v2 metrics

NOTE: The following CVSS v2 metrics and score provided are preliminary and subject to review.

Base Score 3.5
Base Metrics AV:N/AC:M/Au:S/C:N/I:N/A:P
Access Vector Network
Access Complexity Medium
Authentication Single
Confidentiality Impact None
Integrity Impact None
Availability Impact Partial

Find out more about Red Hat support for the Common Vulnerability Scoring System (CVSS).

Affected Packages State

Platform Package State
Red Hat JBoss EWS 1 httpd Will not fix
Red Hat Enterprise Linux 6 httpd Will not fix
Red Hat Enterprise Linux 5 httpd Will not fix
Red Hat Enterprise Linux 4 httpd Will not fix
Red Hat Directory Server 8 httpd Will not fix
Red Hat Certificate System 7.3 for 4AS httpd Will not fix
Unless explicitly stated as not affected, all previous versions of packages in any minor update stream of a product listed here should be assumed vulnerable, although may not have been subject to full analysis.
Last Modified

CVE description copyright © 2017, The MITRE Corporation