{"id":"DEBIAN-CVE-2018-20852","details":"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.","modified":"2026-07-28T06:05:28.348832126Z","published":"2019-07-13T21:15:10.377Z","upstream":["CVE-2018-20852"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2018-20852"}],"affected":[{"package":{"name":"python2.7","ecosystem":"Debian:11","purl":"pkg:deb/debian/python2.7?arch=source&distro=bullseye"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.7.16-3"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2018-20852.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N"}]}