CVE-2018-20852

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.

• CVE ID
• CVE-2018-20852

• Assigner
• cve@mitre.org

• Vulnerability Status
• Modified

• Published Version
• 2019-07-13T21:15:10

• Last Modified Date
• 2020-08-22T17:15:15

• Version
• 2.0

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

• Access Vector
• NETWORK

• Access Compatibility
• LOW

• Authentication
• NONE

• Confidentiality Impact
• PARTIAL

• Integrity Impact
• NONE

• Availability Impact
• NONE

• Base Score
• 5

• Severity
• MEDIUM

• Exploitability Score
• 10

• Impact Score
• 2.9

• Version
• 3.0

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

• Attack Vector
• NETWORK

• Attack Compatibility
• LOW

• Privileges Required
• NONE

• User Interaction
• NONE

• Scope
• UNCHANGED

• Confidentiality Impact
• LOW

• Availability Impact
• NONE

• Base Score
• 5.3

• Base Severity
• MEDIUM

• Exploitability Score
• 3.9

• Impact Score
• 1.4