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CVE-2020-7212 Detail

Description

The _encode_invalid_chars function in util/url.py in the urllib3 library 1.25.2 through 1.25.7 for Python allows a denial of service (CPU consumption) because of an inefficient algorithm. The percent_encodings array contains all matches of percent encodings. It is not deduplicated. For a URL of length N, the size of percent_encodings may be up to O(N). The next step (normalize existing percent-encoded bytes) also takes up to O(N) for each step, so the total time is O(N^2). If percent_encodings were deduplicated, the time to compute _encode_invalid_chars would be O(kN), where k is at most 484 ((10+6*2)^2).


Metrics

NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
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/urllib3/urllib3/blob/master/CHANGES.rst Release Notes  Third Party Advisory 
https://github.com/urllib3/urllib3/commit/a74c9cfbaed9f811e7563cfc3dce894928e0221a Patch  Third Party Advisory 
https://pypi.org/project/urllib3/1.25.8/ Release Notes  Vendor Advisory 

Weakness Enumeration

CWE-ID CWE Name Source
CWE-400 Uncontrolled Resource Consumption cwe source acceptance level NIST  

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Change History

2 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2020-7212
NVD Published Date:
03/06/2020
NVD Last Modified:
03/09/2020
Source:
MITRE