nginx before versions 1.15.6 and 1.14.1 has a vulnerability in the implementation of HTTP/2 that can allow for excessive CPU usage. This issue affects nginx compiled with the ngx_http_v2_module (not compiled by default) if the http2 option of the listen directive is used in a configuration file.
The product does not properly control the allocation and maintenance of a limited resource.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Nginx | F5 | 1.9.5 (including) | 1.14.1 (excluding) |
| Nginx | F5 | 1.15.0 (including) | 1.15.6 (excluding) |
| Red Hat Software Collections for Red Hat Enterprise Linux 7 | RedHat | rh-nginx112-nginx-1:1.12.1-2.el7.1 | * |
| Red Hat Software Collections for Red Hat Enterprise Linux 7 | RedHat | rh-nginx114-nginx-1:1.14.1-1.el7 | * |
| Red Hat Software Collections for Red Hat Enterprise Linux 7.4 EUS | RedHat | rh-nginx112-nginx-1:1.12.1-2.el7.1 | * |
| Red Hat Software Collections for Red Hat Enterprise Linux 7.4 EUS | RedHat | rh-nginx114-nginx-1:1.14.1-1.el7 | * |
| Red Hat Software Collections for Red Hat Enterprise Linux 7.5 EUS | RedHat | rh-nginx112-nginx-1:1.12.1-2.el7.1 | * |
| Red Hat Software Collections for Red Hat Enterprise Linux 7.5 EUS | RedHat | rh-nginx114-nginx-1:1.14.1-1.el7 | * |
| Red Hat Software Collections for Red Hat Enterprise Linux 7.6 EUS | RedHat | rh-nginx112-nginx-1:1.12.1-2.el7.1 | * |
| Red Hat Software Collections for Red Hat Enterprise Linux 7.6 EUS | RedHat | rh-nginx114-nginx-1:1.14.1-1.el7 | * |
| Nginx | Ubuntu | bionic | * |
| Nginx | Ubuntu | cosmic | * |
| Nginx | Ubuntu | devel | * |
| Nginx | Ubuntu | esm-infra/bionic | * |
| Nginx | Ubuntu | esm-infra/xenial | * |
| Nginx | Ubuntu | upstream | * |
| Nginx | Ubuntu | xenial | * |
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.