CVE-2018-20852

MEDIUM

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.

References

http://lists.opensuse.org/opensuse-security-announce/2019-08/msg00071.html

http://lists.opensuse.org/opensuse-security-announce/2019-08/msg00074.html

https://bugs.python.org/issue35121

https://lists.debian.org/debian-lts-announce/2019/08/msg00022.html

https://lists.debian.org/debian-lts-announce/2019/08/msg00040.html

https://python-security.readthedocs.io/vuln/cookie-domain-check.html

Details

Source: MITRE

Published: 2019-07-13

Updated: 2019-08-17

Type: CWE-20

Risk Information

CVSS v2.0

Base Score: 5

Vector: AV:N/AC:L/Au:N/C:P/I:N/A:N

Impact Score: 2.9

Exploitability Score: 10

Severity: MEDIUM

CVSS v3.0

Base Score: 5.3

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Impact Score: 1.4

Exploitability Score: 3.9

Severity: MEDIUM