Description
By specially crafting HTTP/2 requests, workers would be allocated 60 seconds longer than necessary, leading to worker exhaustion and a denial of service. Fixed in Apache HTTP Server 2.4.34 (Affected 2.4.18-2.4.30,2.4.33).
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Apache Software Foundation | Apache HTTP Server | Fixed in Apache HTTP Server 2.4.34 (Affected 2.4.18-2.4.30,2.4.33) | — |
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 | 2.4.34-1 | — |
| Debian 13 | apache2 | 2.4.34-1 | — |
| Debian 12 | apache2 | 2.4.34-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | apache2 | 2.4.29-1ubuntu4.4 | USN-3783-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 3 | httpd24-curl +2 | 7.61.1-1.el6 | RHSA-2018:3558 |
| RHEL 3 | httpd24-httpd +5 | 2.4.34-7.el6 | RHSA-2018:3558 |
| RHEL 3 | httpd24-mod_md | 2.4.34-7.el7 | RHSA-2018:3558 |
| RHEL 3 | httpd24-mod_ssl +1 | 1:2.4.34-7.el6 | RHSA-2018:3558 |
| RHEL 3 | httpd24-nghttp2 +2 | 1.7.1-7.el6 | RHSA-2018:3558 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat JBoss Core Services 1 | jbcs-httpd24 +1 | 1-6.jbcs.el6 | RHSA-2019:0367 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-apache-commons-daemon-jsvc | 1:1.1.0-3.redhat_2.jbcs.el6 | RHSA-2019:0367 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-apr +1 | 1.6.3-31.jbcs.el6 | RHSA-2019:0367 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-apr-util +8 | 1.6.1-24.jbcs.el6 | RHSA-2019:0367 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-httpd +6 | 2.4.29-35.jbcs.el6 | RHSA-2019:0367 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-mod_cluster-native | 1.3.8-3.Final_redhat_2.jbcs.el6 | RHSA-2019:0367 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-mod_jk +2 | 1.2.46-1.redhat_1.jbcs.el6 | RHSA-2019:0367 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-mod_ssl +1 | 1:2.4.29-35.jbcs.el6 | RHSA-2019:0367 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-nghttp2 +1 | 1.29.0-9.jbcs.el6 | RHSA-2019:0367 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-openssl +4 | 1:1.0.2n-14.jbcs.el6 | RHSA-2019:0367 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 | apache2 | 2.4.33-3.3.1 | SUSE-SU-2018:2424-1 |
| SLES 12 SP3 | apache2 | 2.4.23-29.21.1 | SUSE-SU-2018:2336-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 12 SP3 | apache2 | 2.4.23-29.21.1 | SUSE-SU-2018:2336-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | apache2 | 2.4.34-r0 | — |
| Alpine v3.23 | apache2 | 2.4.34-r0 | — |
| Alpine v3.22 | apache2 | 2.4.34-r0 | — |
| Alpine v3.21 | apache2 | 2.4.34-r0 | — |
| Alpine v3.20 | apache2 | 2.4.34-r0 | — |
Show 15 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | apache2 | 2.4.34-r0 | — |
| Alpine v3.18 | apache2 | 2.4.34-r0 | — |
| Alpine v3.17 | apache2 | 2.4.34-r0 | — |
| Alpine v3.16 | apache2 | 2.4.34-r0 | — |
| Alpine v3.15 | apache2 | 2.4.34-r0 | — |
| Alpine v3.14 | apache2 | 2.4.34-r0 | — |
| Alpine v3.13 | apache2 | 2.4.34-r0 | — |
| Alpine v3.12 | apache2 | 2.4.34-r0 | — |
| Alpine v3.11 | apache2 | 2.4.34-r0 | — |
| Alpine v3.10 | apache2 | 2.4.34-r0 | — |
| Alpine v3.9 | apache2 | 2.4.34-r0 | — |
| Alpine v3.8 | apache2 | 2.4.34-r0 | — |
| Alpine v3.7 | apache2 | 2.4.34-r0 | — |
| Alpine v3.6 | apache2 | 2.4.34-r0 | — |
| Alpine v3.5 | apache2 | 2.4.34-r0 | — |
Advisories 5
- RHSA-2019:0367 Red Hat Security Advisory: Red Hat JBoss Core Services Apache HTTP Server 2.4.29 security update Red Hat Security Advisories (RHSA) · Sep 21, 2026
- RHSA-2018:3558 Red Hat Security Advisory: httpd24 security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Sep 21, 2026
- USN-3783-1 apache2 vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- SUSE-SU-2018:2336-1 Security update for apache2 SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:2424-1 Security update for apache2 SUSE / openSUSE Security Updates · May 2, 2025
References
- RHSA-2018:3558 vendor-advisory
- https://support.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbux03909en_us
- RHSA-2019:0367 vendor-advisory
- https://security.netapp.com/advisory/ntap-20180926-0007/
- https://httpd.apache.org/security/vulnerabilities_24.html#CVE-2018-1333
- USN-3783-1 vendor-advisory
- 1041402 vdb-entry
- RHSA-2019:0366 vendor-advisory
- [httpd-cvs] 20190815 svn commit: r1048743 [4/4] - 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 [4/4] - 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
- https://www.tenable.com/security/tns-2019-09
- [httpd-cvs] 20200401 svn commit: r1058586 [4/4] - 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 [4/4] - 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: r1073143 [3/3] - in /websites/staging/httpd/trunk/content: ./ security/ mailing-list
- [httpd-cvs] 20210330 svn commit: r1073140 [4/4] - 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 [11/13] - in /websites/staging/httpd/trunk/content: ./ security/json/ mailing-list
- [httpd-cvs] 20210330 svn commit: r1888194 [12/13] - /httpd/site/trunk/content/security/json/ mailing-list
- [httpd-cvs] 20210330 svn commit: r1073149 [1/13] - in /websites/staging/httpd/trunk/content: ./ security/ security/json/ mailing-list
- [httpd-cvs] 20210330 svn commit: r1073149 [12/13] - in /websites/staging/httpd/trunk/content: ./ security/ security/json/ mailing-list
- [httpd-cvs] 20210606 svn commit: r1075470 [4/4] - 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