CVE-2018-20852 Information

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 Vector

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

Reference

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/issue35121 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@lists.fedoraproject.org/message/COATURTCY7G67AYI6UDV5B2JZTBCKIDX/ https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/K7HNVIFMETMFWWWUNTB72KYJYXCZOS5V/ https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/ZBTGPBUABGXZ7WH7677OEM3NSP6ZEA76/ https://python-security.readthedocs.io/vuln/cookie-domain-check.html https://security.gentoo.org/glsa/202003-26 https://usn.ubuntu.com/4127-1/ https://usn.ubuntu.com/4127-2/ https://www.oracle.com/security-alerts/cpuapr2020.html

Attack Complexity

LOW

Privileges Required

NONE

User Interaction Required

NONE

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

LOW

Availability Impact

NONE

Base Score

NONE

Base Severity

5.3

Share on: