Description
The log_cookie function in mod_log_config.c in the mod_log_config module in the Apache HTTP Server 2.2.17 through 2.2.21, when a threaded MPM is used, does not properly handle a %{}C format string, which allows remote attackers to cause a denial of service (daemon crash) via a cookie that lacks both a name and a value.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | apache2 | 2.2.22-1 | — |
| Debian 13 | apache2 | 2.2.22-1 | — |
| Debian 12 | apache2 | 2.2.22-1 | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat JBoss Web Server 1 | httpd +2 | 2.2.17-15.4.ep5.el5 | RHSA-2012:0542 |
| Red Hat JBoss Web Server 1 | httpd-tools | 2.2.17-15.4.ep5.el6 | RHSA-2012:0542 |
| Red Hat JBoss Web Server 1 | mod_ssl | 1:2.2.17-15.4.ep5.el5 | RHSA-2012:0542 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 11 SP4 | apache2 | 2.2.34-70.12.1 | SUSE-SU-2017:2907-1 |
| SLES 11 SP3 | apache2 | 2.2.34-70.12.1 | SUSE-SU-2017:2907-1 |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SUSE Studio Onsite 1.3 | apache2 | 2.2.34-70.12.1 | SUSE-SU-2017:2907-1 |
| SLES for SAP 11 SP4 | apache2 | 2.2.34-70.12.1 | SUSE-SU-2017:2907-1 |
| SUSE Linux Enterprise Point of Sale 11 SP3 | apache2 | 2.2.34-70.12.1 | SUSE-SU-2017:2907-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | apache2 | 2.4.23-4.1 | openSUSE-SU-2024:10268-1 |
Advisories 3
- RHSA-2012:0542 Red Hat Security Advisory: httpd security and bug fix update Red Hat Security Advisories (RHSA) · May 15, 2026
- SUSE-SU-2017:2907-1 Security update for apache2 SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:10268-1 apache2-2.4.23-4.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
References
- http://svn.apache.org/viewvc?view=revision&revision=1227292
- HPSBMU02786 vendor-advisory
- MDVSA-2012:012 vendor-advisory
- RHSA-2012:0543 vendor-advisory
- SSRT100772 vendor-advisory
- https://issues.apache.org/bugzilla/show_bug.cgi?id=52256
- https://bugzilla.redhat.com/show_bug.cgi?id=785065
- RHSA-2012:0542 vendor-advisory
- http://httpd.apache.org/security/vulnerabilities_22.html
- APPLE-SA-2012-09-19-2 vendor-advisory
- http://support.apple.com/kb/HT5501
- http://www.oracle.com/technetwork/topics/security/cpujul2012-392727.html
- HPSBUX02761 vendor-advisory
- MDVSA-2013:150 vendor-advisory
- 48551 third-party-advisory
- [httpd-cvs] 20190815 svn commit: r1048743 [3/4] - in /websites/staging/httpd/trunk/content: ./ security/vulnerabilities-httpd.xml security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabilit mailing-list
- [httpd-cvs] 20190815 svn commit: r1048742 [3/4] - in /websites/staging/httpd/trunk/content: ./ security/vulnerabilities-httpd.xml security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabilit mailing-list
- [httpd-cvs] 20200401 svn commit: r1058586 [3/4] - in /websites/staging/httpd/trunk/content: ./ security/vulnerabilities-httpd.xml security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabilit mailing-list
- [httpd-cvs] 20200401 svn commit: r1058587 [3/4] - in /websites/staging/httpd/trunk/content: ./ security/vulnerabilities-httpd.xml security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabilit mailing-list
- [httpd-cvs] 20210330 svn commit: r1073139 [1/13] - in /websites/staging/httpd/trunk/content: ./ security/json/ mailing-list
- [httpd-cvs] 20210330 svn commit: r1073140 [3/4] - in /websites/staging/httpd/trunk/content: ./ security/cvejsontohtml.py security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabilities_24.ht mailing-list
- [httpd-cvs] 20210330 svn commit: r1073139 [8/13] - in /websites/staging/httpd/trunk/content: ./ security/json/ mailing-list
- [httpd-cvs] 20210330 svn commit: r1888194 [8/13] - /httpd/site/trunk/content/security/json/ mailing-list
- [httpd-cvs] 20210330 svn commit: r1073149 [8/13] - in /websites/staging/httpd/trunk/content: ./ security/ security/json/ mailing-list
- [httpd-cvs] 20210330 svn commit: r1073146 [2/3] - in /websites/staging/httpd/trunk/content: ./ security/cvejsontohtml.py security/vulnerabilities-httpd.xml security/vulnerabilities_22.html security/vulnerabilities_24.html mailing-list
- [httpd-cvs] 20210330 svn commit: r1073149 [1/13] - in /websites/staging/httpd/trunk/content: ./ security/ security/json/ mailing-list
- [httpd-cvs] 20210603 svn commit: r1075360 [2/3] - in /websites/staging/httpd/trunk/content: ./ security/json/CVE-2021-31618.json security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabiliti mailing-list
- [httpd-cvs] 20210606 svn commit: r1075470 [3/4] - in /websites/staging/httpd/trunk/content: ./ security/json/CVE-2020-13938.json security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabiliti mailing-list