A Regular Expression Denial of Service (ReDoS) issue was discovered in the sanitize_html function of redcloth gem v4.0.0. This vulnerability allows attackers to cause a Denial of Service (DoS) via supplying a crafted payload.
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 |
|---|---|---|---|
| Redcloth | Promptworks | 4.0.0 (including) | 4.3.2 (including) |
| Ruby-redcloth | Ubuntu | bionic | * |
| Ruby-redcloth | Ubuntu | devel | * |
| Ruby-redcloth | Ubuntu | esm-apps/bionic | * |
| Ruby-redcloth | Ubuntu | esm-apps/xenial | * |
| Ruby-redcloth | Ubuntu | focal | * |
| Ruby-redcloth | Ubuntu | jammy | * |
| Ruby-redcloth | Ubuntu | kinetic | * |
| Ruby-redcloth | Ubuntu | lunar | * |
| Ruby-redcloth | Ubuntu | trusty | * |
| Ruby-redcloth | Ubuntu | upstream | * |
| Ruby-redcloth | 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.