CVE-2021-41168 Information

Description

Snudown is a reddit-specific fork of the Sundown Markdown parser used by GitHub with Python integration added. In affected versions snudown was found to be vulnerable to denial of service attacks to its reference table implementation. References written in markdown [reference_name]: https://www.example.com are inserted into a hash table which was found to have a weak hash function meaning that an attacker can reliably generate a large number of collisions for it. This makes the hash table vulnerable to a hash-collision DoS attack a type of algorithmic complexity attack. Further the hash table allowed for duplicate entries resulting in long retrieval times. Proofs of concept and further discussion of the hash collision issue are discussed on the snudown GHSA(https://github.com/reddit/snudown/security/advisories/GHSA-6gvv-9q92-w5f6). Users are advised to update to version 1.7.0.

CVSS Vector

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

Reference

https://github.com/reddit/snudown/security/advisories/GHSA-6gvv-9q92-w5f6 https://github.com/reddit/snudown/commit/1ac2c130b210539ee1e5d67a7bac93f9d8007c0e

Attack Complexity

LOW

Privileges Required

LOW

User Interaction Required

LOW

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

NONE

Availability Impact

NONE

Base Score

HIGH

Base Severity

6.5