CVE-2023-45813 – torbot

Package

Manager: pip
Name: torbot
Vulnerable Version: >=0 <4.0.0

Severity

Level: Medium

CVSS v3.1: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS v4.0: CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

EPSS: 0.00552 pctl0.67041

Details

TorBot vulnerable to Inefficient Regular Expression Complexity in validate_link ### Summary _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.._ ### Details https://github.com/DedSecInside/TorBot/blob/d2b89192379ad033ffc7044efff26e16ccc02d5a/torbot/modules/validators.py#L13 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. ### PoC I have uploaded a secret gist containing a PoC (https://gist.github.com/ikkebr/6041055314f1cfb8e65b2a1acbaae12c). By adding one special character at the end of the user argument of the URL, the regular expression will take exponentially longer to compute. For a string of size 10k, the regex will take 0.01s without the well-crafted URL and 1.3s with the well-crafted URL exploit. For a string of size 50k, the regex will take 0.03s without the well-crafted URL and 35s with the well-crafted URL exploit. For a string of size 100k, the regex will take 0.05s without the well-crafted URL and over 200s with the well-crafted URL exploit. The regular expression used in the validators library versions [0.20, 0.11] is vulnerable to this attack. Version 0.21 appears to be unaffected, but it no longer contains a single regular expression. ### Impact An attacker could exploit this vulnerability to cause a denial of service or increased resource usage.

Metadata

Created: 2023-10-19T12:33:03Z
Modified: 2023-10-19T12:33:03Z
Source: https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2023/10/GHSA-72qw-p7hh-m3ff/GHSA-72qw-p7hh-m3ff.json
CWE IDs: ["CWE-1333"]
Alternative ID: GHSA-72qw-p7hh-m3ff
Finding: F211
Auto approve: 1