Coordinated Disclosure Timeline
- 2021-08-31: Created an issue asking for contact details.
- 2023-03-03: Issue closed.
- 2023-03-07: Confirmed that the poc still works.
- 2023-03-07: Posted a comment asking for contact details.
- 2023-03-08: In response to my comment, @joe733 added a security.md to the repo
- 2023-03-09: I emailed the report to @joe733.
- 2023-03-16: Created a PR to fix the issue: https://github.com/python-validators/validators/pull/243
- 2023-03-17: Received an email from @joe733, notifying that a more comprehensive fix is in progress: https://github.com/python-validators/validators/pull/245
- 2023-03-18: Fix merged: https://github.com/python-validators/validators/pull/245
Summary
validators contains a regular expression that is vulnerable to ReDoS (Regular Expression Denial of Service).
Product
validators
Tested Version
Details
ReDoS
ReDoS, or Regular Expression Denial of Service, is a vulnerability affecting inefficient regular expressions which can perform extremely badly when run on a crafted input string.
Vulnerability
The vulnerable regular expression is here
Please follow these steps to reproduce the issue:
- Install validators:
pip3 install validators - Run the code below with
python3:
import validators
# Doesn't terminate!
print(validators.url("http://0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00."))
This vulnerability was found by the CodeQL ReDoS query for Python, which was still experimental when it found this bug in 2021, but is now included in the standard suite of queries used by code scanning.
Impact
This issue may lead to a denial of service.
Credit
This issue was discovered by GitHub team members @erik-krogh (Erik Krogh Kristensen) and @yoff (Rasmus Petersen).
Contact
You can contact the GHSL team at securitylab@github.com, please include a reference to GHSL-2021-110 in any communication regarding this issue.