CVE-2018-20852

Vulnerability 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.

CVSS Score

Affected Products

Related Weaknesses (CWE)

References

• http://lists.opensuse.org/opensuse-security-announce/2019-08/msg00071.html
• http://lists.opensuse.org/opensuse-security-announce/2019-08/msg00074.html
• http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00040.html
• https://access.redhat.com/errata/RHSA-2019:3725
• https://access.redhat.com/errata/RHSA-2019:3948
• https://bugs.python.org/issue35121ExploitIssue TrackingVendor Advisory
• https://lists.debian.org/debian-lts-announce/2019/08/msg00022.html
• https://lists.debian.org/debian-lts-announce/2019/08/msg00040.html
• https://lists.debian.org/debian-lts-announce/2020/07/msg00011.html
• https://lists.debian.org/debian-lts-announce/2020/08/msg00034.html
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
• https://python-security.readthedocs.io/vuln/cookie-domain-check.htmlVendor Advisory
• https://security.gentoo.org/glsa/202003-26