CVE-2018-20852

Public on 2019-07-13
Modified on 2020-08-31
Description

http.cookiejar.DefaultPolicy.domain_return_ok in Lib/http/cookiejar.py in Python before 3.7.3 does not correctly validate the domain: it can be tricked into sending existing cookies to the wrong server. An attacker may abuse this flaw by using a server with a hostname that has another valid hostname as a suffix (e.g., pythonicexample.com to steal cookies for example.com). When a program uses http.cookiejar.DefaultPolicy and tries to do an HTTP connection to an attacker-controlled server, existing cookies can be leaked to the attacker. This affects 2.x through 2.7.16, 3.x before 3.4.10, 3.5.x before 3.5.7, 3.6.x before 3.6.9, and 3.7.x before 3.7.3.

Severity
Medium
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CVSS v3 Base Score
5.3
See breakdown

Affected Packages

Platform Package Release Date Advisory
Amazon Linux 2 python 2020-06-01 22:38 ALAS2-2020-1432
Amazon Linux 1 python27 2020-05-22 20:58 ALAS-2020-1375

CVSS Scores

Score Type Score Vector
Amazon Linux CVSSv3 5.3 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
NVD CVSSv2 5.0 AV:N/AC:L/Au:N/C:P/I:N/A:N
NVD CVSSv3 5.3 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N