Id:
CVE-2020-7212
Comment
:
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).
CVSSv2 Score:
7.8
Access vector:
|
NETWORK
|
Access complexity:
|
LOW
|
Authentication:
|
NONE
|
Confidentiality impact:
|
NONE
|
Integrity impact:
|
NONE
|
Availability impact:
|
COMPLETE
|
CVSSv2 Vector:
AV:N/AC:L/Au:N/C:N/I:N/A:C
CVSSv3 Score:
7.5
Attack vector:
|
NETWORK
|
Attack complexity:
|
LOW
|
Privileges required:
|
NONE
|
User interaction:
|
NONE
|
Scope:
|
UNCHANGED
|
Confidentiality impact:
|
NONE
|
Integrity impact:
|
NONE
|
Availability impact:
|
HIGH
|
CVSSv3 Vector:
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
References: