CVE-2018-20852

MEDIUM severity · CVSS 5.3 · Improper input validation

5.3CVSS MEDIUM

Summary

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.

Impact & exploitability

Attack vectorNetwork

Attack complexityLow

Privileges requiredNone

User interactionNone

Confidentiality impactLow

Integrity impactNone

Availability impactNone

Exploit probability (EPSS)2%

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

Affected products we track (1)

Python

Recommendation

Apply the vendor fix in your normal patch cycle. Open any affected product above for its exact safe version.

CVE-2018-20852

Summary

Impact & exploitability

Affected products we track (1)

Recommendation

Additional information