CVE-2020-7212

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).

Risk Information

Base Score
7.5
MODERATE
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score
Exploitation Probability
0.677

Associated Vulnerability

VulnerabilityOS Platform
Vulnerabilities CVE-2020-7212 are fixed in Python-urllib3 1.25.8Windows
Vulnerabilities CVE-2020-7212 are fixed in Python-urllib3 for linux 1.25.8Linux
Uncontrolled Resource Consumption Vulnerability (CVE-2020-7212)NCM

Patch Details

No records found

References

https://nvd.nist.gov/vuln/detail/CVE-2023-1234
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-1234