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).
The product does not properly control the allocation and maintenance of a limited resource.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Http_server | Apache | 2.4.18 (including) | 2.4.30 (including) |
| Http_server | Apache | 2.4.33 (including) | 2.4.33 (including) |
| JBoss Core Services on RHEL 6 | RedHat | jbcs-httpd24-0:1-6.jbcs.el6 | * |
| JBoss Core Services on RHEL 6 | RedHat | jbcs-httpd24-apache-commons-daemon-jsvc-1:1.1.0-3.redhat_2.jbcs.el6 | * |
| JBoss Core Services on RHEL 6 | RedHat | jbcs-httpd24-apr-0:1.6.3-31.jbcs.el6 | * |
| JBoss Core Services on RHEL 6 | RedHat | jbcs-httpd24-apr-util-0:1.6.1-24.jbcs.el6 | * |
| JBoss Core Services on RHEL 6 | RedHat | jbcs-httpd24-httpd-0:2.4.29-35.jbcs.el6 | * |
| JBoss Core Services on RHEL 6 | RedHat | jbcs-httpd24-mod_cluster-native-0:1.3.8-3.Final_redhat_2.jbcs.el6 | * |
| JBoss Core Services on RHEL 6 | RedHat | jbcs-httpd24-mod_jk-0:1.2.46-1.redhat_1.jbcs.el6 | * |
| JBoss Core Services on RHEL 6 | RedHat | jbcs-httpd24-nghttp2-0:1.29.0-9.jbcs.el6 | * |
| JBoss Core Services on RHEL 6 | RedHat | jbcs-httpd24-openssl-1:1.0.2n-14.jbcs.el6 | * |
| JBoss Core Services on RHEL 7 | RedHat | jbcs-httpd24-0:1-6.jbcs.el7 | * |
| JBoss Core Services on RHEL 7 | RedHat | jbcs-httpd24-apache-commons-daemon-jsvc-1:1.1.0-3.redhat_2.jbcs.el7 | * |
| JBoss Core Services on RHEL 7 | RedHat | jbcs-httpd24-apr-0:1.6.3-31.jbcs.el7 | * |
| JBoss Core Services on RHEL 7 | RedHat | jbcs-httpd24-apr-util-0:1.6.1-24.jbcs.el7 | * |
| JBoss Core Services on RHEL 7 | RedHat | jbcs-httpd24-httpd-0:2.4.29-35.jbcs.el7 | * |
| JBoss Core Services on RHEL 7 | RedHat | jbcs-httpd24-mod_cluster-native-0:1.3.8-3.Final_redhat_2.jbcs.el7 | * |
| JBoss Core Services on RHEL 7 | RedHat | jbcs-httpd24-mod_jk-0:1.2.46-1.redhat_1.jbcs.el7 | * |
| JBoss Core Services on RHEL 7 | RedHat | jbcs-httpd24-nghttp2-0:1.29.0-9.jbcs.el7 | * |
| JBoss Core Services on RHEL 7 | RedHat | jbcs-httpd24-openssl-1:1.0.2n-14.jbcs.el7 | * |
| Red Hat Software Collections for Red Hat Enterprise Linux 6 | RedHat | httpd24-curl-0:7.61.1-1.el6 | * |
| Red Hat Software Collections for Red Hat Enterprise Linux 6 | RedHat | httpd24-httpd-0:2.4.34-7.el6 | * |
| Red Hat Software Collections for Red Hat Enterprise Linux 6 | RedHat | httpd24-nghttp2-0:1.7.1-7.el6 | * |
| Red Hat Software Collections for Red Hat Enterprise Linux 7 | RedHat | httpd24-curl-0:7.61.1-1.el7 | * |
| Red Hat Software Collections for Red Hat Enterprise Linux 7 | RedHat | httpd24-httpd-0:2.4.34-7.el7 | * |
| Red Hat Software Collections for Red Hat Enterprise Linux 7 | RedHat | httpd24-nghttp2-0:1.7.1-7.el7 | * |
| Red Hat Software Collections for Red Hat Enterprise Linux 7.4 EUS | RedHat | httpd24-curl-0:7.61.1-1.el7 | * |
| Red Hat Software Collections for Red Hat Enterprise Linux 7.4 EUS | RedHat | httpd24-httpd-0:2.4.34-7.el7 | * |
| Red Hat Software Collections for Red Hat Enterprise Linux 7.4 EUS | RedHat | httpd24-nghttp2-0:1.7.1-7.el7 | * |
| Red Hat Software Collections for Red Hat Enterprise Linux 7.5 EUS | RedHat | httpd24-curl-0:7.61.1-1.el7 | * |
| Red Hat Software Collections for Red Hat Enterprise Linux 7.5 EUS | RedHat | httpd24-httpd-0:2.4.34-7.el7 | * |
| Red Hat Software Collections for Red Hat Enterprise Linux 7.5 EUS | RedHat | httpd24-nghttp2-0:1.7.1-7.el7 | * |
| Red Hat Software Collections for Red Hat Enterprise Linux 7.6 EUS | RedHat | httpd24-curl-0:7.61.1-1.el7 | * |
| Red Hat Software Collections for Red Hat Enterprise Linux 7.6 EUS | RedHat | httpd24-httpd-0:2.4.34-7.el7 | * |
| Red Hat Software Collections for Red Hat Enterprise Linux 7.6 EUS | RedHat | httpd24-nghttp2-0:1.7.1-7.el7 | * |
| Text-Only JBCS | RedHat | httpd | * |
| Apache2 | Ubuntu | bionic | * |
| Apache2 | Ubuntu | devel | * |
| Apache2 | Ubuntu | esm-infra/bionic | * |
| Apache2 | Ubuntu | upstream | * |
Mitigation of resource exhaustion attacks requires that the target system either:
The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question.
The second solution is simply difficult to effectively institute – and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.