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).
Analysis and contextual insights are available on OpenCVE Cloud.
Remediation
No vendor fix or workaround currently provided.
Additional remediation guidance may be available on OpenCVE Cloud.
Tracking
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Advisories
| Source | ID | Title |
|---|---|---|
EUVD |
EUVD-2020-0231 | 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). |
Github GHSA |
GHSA-hmv2-79q8-fv6g | Uncontrolled Resource Consumption in urllib3 |
References
History
No history.
Status: PUBLISHED
Assigner: mitre
Published:
Updated: 2024-08-04T09:25:48.318Z
Reserved: 2020-01-16T00:00:00.000Z
Link: CVE-2020-7212
No data.
Status : Modified
Published: 2020-03-06T20:15:12.707
Modified: 2024-11-21T05:36:50.467
Link: CVE-2020-7212
OpenCVE Enrichment
No data.
Weaknesses
EUVD
Github GHSA