CVE-2020-7212
First published: Fri Mar 06 2020(Updated: )
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).
Credit: cve@mitre.org
| Affected Software | Affected Version | How to fix |
|---|---|---|
| Python urllib3 | >=1.25.2<=1.25.7 |
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Reference Links
Frequently Asked Questions
What is CVE-2020-7212?
CVE-2020-7212 is a vulnerability in the urllib3 library for Python that allows a denial of service (CPU consumption) due to an inefficient algorithm in the _encode_invalid_chars function.
How severe is CVE-2020-7212?
CVE-2020-7212 has a severity rating of 7.5 (high).
Which software is affected by CVE-2020-7212?
The urllib3 library versions 1.25.2 through 1.25.7 for Python are affected by CVE-2020-7212.
How can I fix CVE-2020-7212?
To fix CVE-2020-7212, upgrade to urllib3 version 1.25.8 or later.
Where can I find more information about CVE-2020-7212?
You can find more information about CVE-2020-7212 in the references provided: [link1], [link2], [link3].
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- version/python urllib3/1.25.7