Rack is a modular Ruby web server interface. Carefully crafted headers can cause header parsing in Rack to take longer than expected resulting in a possible denial of service issue. Accept and Forwarded headers are impacted. Ruby 3.2 has mitigations for this problem, so Rack applications using Ruby 3.2 or newer are unaffected. This vulnerability is fixed in 2.0.9.4, 2.1.4.4, 2.2.8.1, and 3.0.9.1.
The product uses a regular expression with an inefficient, possibly exponential worst-case computational complexity that consumes excessive CPU cycles.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Red Hat Enterprise Linux 8 | RedHat | pcs-0:0.10.18-2.el8_10 | * |
| Red Hat Enterprise Linux 8.2 Telecommunications Update Service | RedHat | pcs-0:0.10.4-6.el8_2.5 | * |
| Red Hat Enterprise Linux 8.2 Update Services for SAP Solutions | RedHat | pcs-0:0.10.4-6.el8_2.5 | * |
| Red Hat Enterprise Linux 8.4 Telecommunications Update Service | RedHat | pcs-0:0.10.8-1.el8_4.5 | * |
| Red Hat Enterprise Linux 8.4 Update Services for SAP Solutions | RedHat | pcs-0:0.10.8-1.el8_4.5 | * |
| Red Hat Enterprise Linux 8.6 Extended Update Support | RedHat | pcs-0:0.10.12-6.el8_6.5 | * |
| Red Hat Enterprise Linux 8.8 Extended Update Support | RedHat | pcs-0:0.10.15-4.el8_8.2 | * |
| Red Hat Enterprise Linux 9 | RedHat | pcs-0:0.11.7-2.el9_4 | * |
| Red Hat Enterprise Linux 9.0 Extended Update Support | RedHat | pcs-0:0.11.1-10.el9_0.5 | * |
| Red Hat Enterprise Linux 9.2 Extended Update Support | RedHat | pcs-0:0.11.4-7.el9_2.1 | * |
| Red Hat Satellite 6.15 for RHEL 8 | RedHat | rubygem-rack-0:2.2.8.1-1.el8sat | * |
| Red Hat Satellite 6.15 for RHEL 8 | RedHat | rubygem-rack-0:2.2.8.1-1.el8sat | * |
| Ruby-rack | Ubuntu | bionic | * |
| Ruby-rack | Ubuntu | esm-apps/bionic | * |
| Ruby-rack | Ubuntu | esm-apps/focal | * |
| Ruby-rack | Ubuntu | esm-apps/jammy | * |
| Ruby-rack | Ubuntu | esm-apps/xenial | * |
| Ruby-rack | Ubuntu | jammy | * |
| Ruby-rack | Ubuntu | mantic | * |
| Ruby-rack | Ubuntu | noble | * |
| Ruby-rack | Ubuntu | trusty | * |
| Ruby-rack | Ubuntu | trusty/esm | * |
| Ruby-rack | Ubuntu | upstream | * |
| Ruby-rack | Ubuntu | xenial | * |
Attackers can create crafted inputs that
intentionally cause the regular expression to use
excessive backtracking in a way that causes the CPU
consumption to spike.