There is a denial of service vulnerability in the Content-Disposition parsingcomponent of Rack fixed in 2.0.9.2, 2.1.4.2, 2.2.4.1, 3.0.0.1. This could allow an attacker to craft an input that can cause Content-Disposition header parsing in Rackto take an unexpected amount of time, possibly resulting in a denial ofservice attack vector. This header is used typically used in multipartparsing. Any applications that parse multipart posts using Rack (virtuallyall Rails applications) are impacted.
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 |
|---|---|---|---|
| Rack | Rack_project | 2.0.0 (including) | 2.0.9.2 (excluding) |
| Rack | Rack_project | 2.1.0 (including) | 2.1.4.2 (excluding) |
| Rack | Rack_project | 2.2.0 (including) | 2.2.6.1 (excluding) |
| Rack | Rack_project | 3.0.0.0 (including) | 3.0.4.1 (excluding) |
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.