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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 serve...

MediumCVSS 5.3 EPSS 3.7%
Published
Updated
Exploit status
No public exploit known
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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.

Affected products

ProductAffected versionsFixed in
debian/python2.7(Debian:11) < 2.7.16-3 2.7.16-3
python >= 2.0, <= 2.7.16 No fix listed
python >= 3.0.0, < 3.4.10 3.4.10
python >= 3.5.0, < 3.5.7 3.5.7
python >= 3.6.0, < 3.6.9 3.6.9
python >= 3.7.0, < 3.7.3 3.7.3

References