CVE-2020-7212
Urllib3 Denial of Service
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).
INFO
Published Date :
March 6, 2020, 8:15 p.m.
Last Modified :
March 9, 2020, 4:55 p.m.
Source :
[email protected]
Remotely Exploitable :
Yes !
Impact Score :
3.6
Exploitability Score :
3.9
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2020-7212.
| URL | 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 |
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2020-7212 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2020-7212 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by [email protected]
May. 14, 2024
Action Type Old Value New Value -
Initial Analysis by [email protected]
Mar. 09, 2020
Action Type Old Value New Value Added CVSS V2 NIST (AV:N/AC:L/Au:N/C:N/I:N/A:C) Added CVSS V3.1 NIST AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Changed Reference Type https://github.com/urllib3/urllib3/blob/master/CHANGES.rst No Types Assigned https://github.com/urllib3/urllib3/blob/master/CHANGES.rst Release Notes, Third Party Advisory Changed Reference Type https://github.com/urllib3/urllib3/commit/a74c9cfbaed9f811e7563cfc3dce894928e0221a No Types Assigned https://github.com/urllib3/urllib3/commit/a74c9cfbaed9f811e7563cfc3dce894928e0221a Patch, Third Party Advisory Changed Reference Type https://pypi.org/project/urllib3/1.25.8/ No Types Assigned https://pypi.org/project/urllib3/1.25.8/ Release Notes, Vendor Advisory Added CWE NIST CWE-400 Added CPE Configuration OR *cpe:2.3:a:python:urllib3:*:*:*:*:*:*:*:* versions from (including) 1.25.2 up to (including) 1.25.7
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2020-7212 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2020-7212
weaknesses.
Exploit Prediction
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.
0.20 }} -0.01%
score
0.58322
percentile