CVE-2018-20852

Public on 2020-05-22
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
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