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CVE-2021-41168 Detail

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.


Metrics

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CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

References to Advisories, Solutions, and Tools

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Hyperlink Resource
https://github.com/reddit/snudown/commit/1ac2c130b210539ee1e5d67a7bac93f9d8007c0e Patch  Third Party Advisory 
https://github.com/reddit/snudown/security/advisories/GHSA-6gvv-9q92-w5f6 Exploit  Third Party Advisory 

Weakness Enumeration

CWE-ID CWE Name Source
CWE-407 Inefficient Algorithmic Complexity cwe source acceptance level NIST  
CWE-327 Use of a Broken or Risky Cryptographic Algorithm GitHub, Inc.  
CWE-400 Uncontrolled Resource Consumption GitHub, Inc.  
CWE-20 Improper Input Validation GitHub, Inc.  

Known Affected Software Configurations Switch to CPE 2.2

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Change History

3 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2021-41168
NVD Published Date:
10/21/2021
NVD Last Modified:
07/17/2023
Source:
GitHub, Inc.