Torbot is an open source tor network intelligence tool. In affected versions the torbot.modules.validators.validate_link function uses the python-validators URL validation regex. This particular regular expression has an exponential complexity which allows an attacker to cause an application crash using a well-crafted argument. An attacker can use a well-crafted URL argument to exploit the vulnerability in the regular expression and cause a Denial of Service on the system. The validators file has been removed in version 4.0.0. Users are advised to upgrade. There are no known workarounds for this vulnerability.
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 |
|---|---|---|---|
| Torbot | Torbot_project | * | 4.0.0 (excluding) |
| Validators | Validators_project | 0.11.0 (including) | 0.11.0 (including) |
| Validators | Validators_project | 0.20.0 (including) | 0.20.0 (including) |
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.