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Fencer Vulns
high 7.1

CVE-2009-1891 in the critical feed json

The mod_deflate module in Apache httpd 2.2.11 and earlier compresses large files until completion even after the associated network connect…

published 2009-07-10 17 y ago modified 2026-06-16 4 mo ago also EUVD-2009-1886

cvss
7.1
version 2.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
17.1%
EPSS 17.1% chance of exploitation in 30 days, percentile 97%
public exploits
0
none known

Summary

The mod_deflate module in Apache httpd 2.2.11 and earlier compresses large files until completion even after the associated network connection is closed, which allows remote attackers to cause a denial of service (CPU consumption).

Patch / fix

  • apache http_server 2.0.64, 2.2.12
  • apache2 Debian 14, Debian 13, Debian 12 2.2.11-7

debian advisories DEBIAN-CVE-2009-1891

  • ant certificate system 7.3 1.6.5-1jpp_1rh
  • axis certificate system 7.3 1.2.1-1jpp_3rh
  • mx4j certificate system 7.3 1:3.0.1-1jpp_4rh
  • log4j certificate system 7.3 1.2.12-1jpp_1rh
  • tomcat5 certificate system 7.3 5.5.23-0jpp_4rh.16
  • rhpki-ca certificate system 7.3 7.3.0-20.el4
  • pcsc-lite certificate system 7.3 1.3.3-3.el4
  • rhpki-kra certificate system 7.3 7.3.0-14.el4

red hat advisories RHSA-2010:0602RHSA-2009:1205RHSA-2009:1580RHSA-2009:1160RHSA-2009:1156RHSA-2009:1155

  • apache2 openSUSE Tumbleweed 2.4.23-4.1

opensuse advisories openSUSE-SU-2024:10268-1

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-2009-1891 updated cvss 2.6

httpd: possible temporary DoS (CPU consumption) in mod_deflate

  • Red Hat Certificate System 7.3 for 4AS ant 1.6.5-1jpp_1rh, axis 1.2.1-1jpp_3rh, mx4j 3.0.1-1jpp_4rh, log4j 1.2.12-1jpp_1rh, pcsc-lite 1.3.3-3.el4, rhpki-ca 7.3.0-20.el4, +31 more Red Hat Certificate System 7.3 for 4ES ant 1.6.5-1jpp_1rh, axis 1.2.1-1jpp_3rh, mx4j 3.0.1-1jpp_4rh, log4j 1.2.12-1jpp_1rh, pcsc-lite 1.3.3-3.el4, rhpki-ca 7.3.0-20.el4, +31 more
    fixed: vendor fix RHSA-2010:0602
  • Red Hat Desktop version 3 httpd 2.0.46-75.ent, mod_ssl 2.0.46-75.ent
    fixed: vendor fix RHSA-2009:1205
  • Red Hat Enterprise Linux (v. 5 server) httpd 2.2.3-22.el5_3.2, mod_ssl 2.2.3-22.el5_3.2, httpd-manual 2.2.3-22.el5_3.2
    fixed: vendor fix RHSA-2009:1148
  • Red Hat Enterprise Linux AS version 3 httpd 2.0.46-75.ent, mod_ssl 2.0.46-75.ent
    fixed: vendor fix RHSA-2009:1205
  • Red Hat Enterprise Linux AS version 4 httpd 2.0.52-41.ent.6, mod_ssl 2.0.52-41.ent.6, httpd-manual 2.0.52-41.ent.6, httpd-suexec 2.0.52-41.ent.6
    fixed: vendor fix RHSA-2009:1580
  • Red Hat Enterprise Linux Desktop (v. 5 client) httpd 2.2.3-22.el5_3.2, mod_ssl 2.2.3-22.el5_3.2, httpd-manual 2.2.3-22.el5_3.2
    fixed: vendor fix RHSA-2009:1148
  • Red Hat Enterprise Linux Desktop version 4 httpd 2.0.52-41.ent.6, mod_ssl 2.0.52-41.ent.6, httpd-manual 2.0.52-41.ent.6, httpd-suexec 2.0.52-41.ent.6
    fixed: vendor fix RHSA-2009:1580
  • Red Hat Enterprise Linux Desktop Workstation (v. 5 client) httpd 2.2.3-22.el5_3.2, mod_ssl 2.2.3-22.el5_3.2, httpd-manual 2.2.3-22.el5_3.2
    fixed: vendor fix RHSA-2009:1148
show 6 more
  • Red Hat Enterprise Linux ES version 3 httpd 2.0.46-75.ent, mod_ssl 2.0.46-75.ent
    fixed: vendor fix RHSA-2009:1205
  • Red Hat Enterprise Linux ES version 4 httpd 2.0.52-41.ent.6, mod_ssl 2.0.52-41.ent.6, httpd-manual 2.0.52-41.ent.6, httpd-suexec 2.0.52-41.ent.6
    fixed: vendor fix RHSA-2009:1580
  • Red Hat Enterprise Linux WS version 3 httpd 2.0.46-75.ent, mod_ssl 2.0.46-75.ent
    fixed: vendor fix RHSA-2009:1205
  • Red Hat Enterprise Linux WS version 4 httpd 2.0.52-41.ent.6, mod_ssl 2.0.52-41.ent.6, httpd-manual 2.0.52-41.ent.6, httpd-suexec 2.0.52-41.ent.6
    fixed: vendor fix RHSA-2009:1580
  • Red Hat JBoss Enterprise Web Server 1 for RHEL 5 Server httpd 2.2.10-10.ep5.el5, mod_ssl 2.2.10-10.ep5.el5, httpd-manual 2.2.10-10.ep5.el5
    fixed: vendor fix RHSA-2009:1155
  • Red Hat JBoss Web Server 1.0 for RHEL 4 AS httpd22 2.2.10-23.1.ep5.el4, mod_ssl22 2.2.10-23.1.ep5.el4, httpd22-apr 2.2.10-23.1.ep5.el4, httpd22-apr-util 2.2.10-23.1.ep5.el4 Red Hat JBoss Web Server 1.0 for RHEL 4 ES httpd22 2.2.10-23.1.ep5.el4, mod_ssl22 2.2.10-23.1.ep5.el4, httpd22-apr 2.2.10-23.1.ep5.el4, httpd22-apr-util 2.2.10-23.1.ep5.el4
    fixed: vendor fix RHSA-2009:1160

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

Exploit prediction

17.11% chance of exploitation in the next 30 days, higher than 97% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • marc.info http://marc.info/?l=apache-httpd-dev&m=124621326524824&w=2 referenced PoC, tagged "exploit" by a source, unverified
  • bugs.debian.org http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=534712 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 2.0 7.1 AV:N/AC:M/Au:N/C:N/I:N/A:C

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption
Technology feeds

References

Sources

Fencer Vulns 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.