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Fencer Intel
low 1.2

CVE-2011-4415 json

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 mod…

published 2011-11-08 15 y ago modified 2026-06-16 4 mo ago also EUVD-2011-4344

cvss
1.2
version 2.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
3.0%
EPSS 3.0% chance of exploitation in 30 days, percentile 87%
public exploits
1
Exploit-DB

Summary

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.

Patch / fix

  • apache2 Debian 14, Debian 13, Debian 12 2.4.1-1

debian advisories DEBIAN-CVE-2011-4415

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2011-4415 updated cvss 3.5

httpd: SetEnvIf resource exhaustion

  • Red Hat Directory Server 8 httpd Red Hat Enterprise Linux 4 httpd Red Hat Enterprise Linux 5 httpd Red Hat Enterprise Linux 6 httpd, mod_ssl, httpd-tools, httpd-manual Red Hat JBoss Enterprise Web Server 1 httpd
    affected: no fix planned “Will not fix”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Timeline

  1. First public exploit (EDB-41769)
  2. Published

Exploit prediction

3.02% chance of exploitation in the next 30 days, higher than 87% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • EDB-41769 Apache < 2.0.64 / < 2.2.21 mod_setenvif - Integer Overflow dos, 2011-11-02
  • halfdog.net http://www.halfdog.net/Security/2011/ApacheModSetEnvIfIntegerOverflow/ referenced PoC, tagged "exploit" by a source, unverified
  • halfdog.net http://www.halfdog.net/Security/2011/ApacheModSetEnvIfIntegerOverflow/DemoExploit.html referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 2.0 1.2 AV:L/AC:H/Au:N/C:N/I:N/A:P

Classification

Weakness
  • CWE-20 Improper Input Validation
Technology feeds

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.