{"id":"CVE-2018-20852","revision":"b70b22c2cb59492b8facaf9cc2b441d3","records":[{"revision":"b70b22c2cb59492b8facaf9cc2b441d3","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2018-20852","aliases":[],"title":"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 us…","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.","state":0,"publishedAt":"2019-07-13T20:29:42+00:00","modifiedAt":"2026-10-07T18:24:46.612+00:00","affected":[{"ecosystem":"Vendor product","name":"n/a","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"n/a\",\n                    \"vendor\": \"n/a\",\n                    \"versions\": [\n                        {\n                            \"status\": \"affected\",\n                            \"version\": \"n/a\"\n                        }\n                    ]\n                }"}],"metrics":[],"references":["https://bugs.python.org/issue35121","https://python-security.readthedocs.io/vuln/cookie-domain-check.html","https://lists.debian.org/debian-lts-announce/2019/08/msg00022.html","http://lists.opensuse.org/opensuse-security-announce/2019-08/msg00071.html","http://lists.opensuse.org/opensuse-security-announce/2019-08/msg00074.html","https://lists.debian.org/debian-lts-announce/2019/08/msg00040.html","https://usn.ubuntu.com/4127-2/","https://usn.ubuntu.com/4127-1/","https://access.redhat.com/errata/RHSA-2019:3725","https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/K7HNVIFMETMFWWWUNTB72KYJYXCZOS5V/","https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZBTGPBUABGXZ7WH7677OEM3NSP6ZEA76/","https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/COATURTCY7G67AYI6UDV5B2JZTBCKIDX/","https://access.redhat.com/errata/RHSA-2019:3948","http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00040.html","https://security.gentoo.org/glsa/202003-26","https://www.oracle.com/security-alerts/cpuapr2020.html","https://lists.debian.org/debian-lts-announce/2020/07/msg00011.html","https://lists.debian.org/debian-lts-announce/2020/08/msg00034.html"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2018-20852","license":"CVE Program Terms of Use","key":"cve-program:CVE-2018-20852","identifiers":["CVE-2018-20852"]},"retained":false,"historicalAffected":[]}],"coverage":[]}