CVE-2021-31618
Fixed in a distro release EPSS 51%
Apache HTTP Server protocol handler for the HTTP/2 protocol checks received request headers against the size limitations as configured for the server and used for the HTTP/1 protocol as well. On violation of these restrictions and HTTP response is sent to the client with a status code indicating why the request was rejected. This rejection response was not fully initialised in the HTTP/2 protocol handler if the offending header was the very first one received or appeared in a a footer. This led to a NULL pointer dereference on initialised memory, crashing reliably the child process. Since such a triggering HTTP/2 request is easy to craft and submit, this can be exploited to DoS the server. This issue affected mod_http2 1.15.17 and Apache HTTP Server version 2.4.47 only. Apache HTTP Server 2.4.47 was never released.
Products: Apache Software Foundation Apache HTTP Server
Distro releases
| Release | Package | Fixed in |
|---|---|---|
| Alpine:v3.10 | apache2 | 2.4.48-r0 |
| Alpine:v3.11 | apache2 | 2.4.48-r0 |
| Alpine:v3.12 | apache2 | 2.4.48-r0 |
| Alpine:v3.13 | apache2 | 2.4.48-r0 |
| Alpine:v3.14 | apache2 | 2.4.48-r0 |
| Alpine:v3.15 | apache2 | 2.4.48-r0 |
| Alpine:v3.16 | apache2 | 2.4.48-r0 |
| Alpine:v3.17 | apache2 | 2.4.48-r0 |
| Alpine:v3.18 | apache2 | 2.4.48-r0 |
| Alpine:v3.19 | apache2 | 2.4.48-r0 |
| Alpine:v3.20 | apache2 | 2.4.48-r0 |
| Alpine:v3.21 | apache2 | 2.4.48-r0 |
| Alpine:v3.22 | apache2 | 2.4.48-r0 |
| Alpine:v3.23 | apache2 | 2.4.48-r0 |
| Alpine:v3.24 | apache2 | 2.4.48-r0 |
| Debian:10 | apache2 | 2.4.38-3+deb10u5 |
| Debian:12 | apache2 | 2.4.46-5 |
| Debian:13 | apache2 | 2.4.46-5 |
| Debian:14 | apache2 | 2.4.46-5 |
| Debian:9 | apache2 | 2.4.25-3+deb9u10 |
| SUSE:Enterprise Storage 6 | apache2 | 2.4.33-3.50.1 |
| SUSE:HPE Helion OpenStack 8 | apache2 | 2.4.23-29.74.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP1-ESPOS | apache2 | 2.4.33-3.50.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP1-LTSS | apache2 | 2.4.33-3.50.1 |
| SUSE:Linux Enterprise High Performance Computing 15-ESPOS | apache2 | 2.4.33-3.50.1 |
| SUSE:Linux Enterprise High Performance Computing 15-LTSS | apache2 | 2.4.33-3.50.1 |
| SUSE:Linux Enterprise Module for Basesystem 15 SP2 | apache2 | 2.4.43-3.22.1 |
| SUSE:Linux Enterprise Module for Basesystem 15 SP3 | apache2 | 2.4.43-3.22.1 |
| SUSE:Linux Enterprise Module for Package Hub 15 SP3 | apache2 | 2.4.43-3.22.1 |
| SUSE:Linux Enterprise Module for Server Applications 15 SP2 | apache2 | 2.4.43-3.22.1 |
| SUSE:Linux Enterprise Module for Server Applications 15 SP3 | apache2 | 2.4.43-3.22.1 |
| SUSE:Linux Enterprise Server 12 SP2-BCL | apache2 | 2.4.23-29.74.1 |
| SUSE:Linux Enterprise Server 12 SP3-BCL | apache2 | 2.4.23-29.74.1 |
| SUSE:Linux Enterprise Server 12 SP3-LTSS | apache2 | 2.4.23-29.74.1 |
| SUSE:Linux Enterprise Server 12 SP4-LTSS | apache2 | 2.4.23-29.74.1 |
| SUSE:Linux Enterprise Server 12 SP5 | apache2 | 2.4.23-29.74.1 |
| SUSE:Linux Enterprise Server 15 SP1-BCL | apache2 | 2.4.33-3.50.1 |
| SUSE:Linux Enterprise Server 15 SP1-LTSS | apache2 | 2.4.33-3.50.1 |
| SUSE:Linux Enterprise Server 15-LTSS | apache2 | 2.4.33-3.50.1 |
| SUSE:Linux Enterprise Server for SAP Applications 12 SP3 | apache2 | 2.4.23-29.74.1 |
| SUSE:Linux Enterprise Server for SAP Applications 12 SP4 | apache2 | 2.4.23-29.74.1 |
| SUSE:Linux Enterprise Server for SAP Applications 12 SP5 | apache2 | 2.4.23-29.74.1 |
| SUSE:Linux Enterprise Server for SAP Applications 15 | apache2 | 2.4.33-3.50.1 |
| SUSE:Linux Enterprise Server for SAP Applications 15 SP1 | apache2 | 2.4.33-3.50.1 |
| SUSE:Linux Enterprise Software Development Kit 12 SP5 | apache2 | 2.4.23-29.74.1 |
| SUSE:Manager Proxy 4.0 | apache2 | 2.4.33-3.50.1 |
| SUSE:Manager Retail Branch Server 4.0 | apache2 | 2.4.33-3.50.1 |
| SUSE:Manager Server 4.0 | apache2 | 2.4.33-3.50.1 |
| SUSE:OpenStack Cloud 8 | apache2 | 2.4.23-29.74.1 |
| SUSE:OpenStack Cloud 9 | apache2 | 2.4.23-29.74.1 |
| SUSE:OpenStack Cloud Crowbar 8 | apache2 | 2.4.23-29.74.1 |
| SUSE:OpenStack Cloud Crowbar 9 | apache2 | 2.4.23-29.74.1 |
| openSUSE:Leap 15.2 | apache2 | 2.4.43-lp152.2.15.1 |
| openSUSE:Leap 15.3 | apache2 | 2.4.43-3.22.1 |