#VU22617 Input validation error in Python - CVE-2019-16056

Vulnerability identifier: #VU22617

Vulnerability risk: Low

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2019-16056

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Python
Universal components / Libraries / Scripting languages

Vendor: Python.org

Description

The vulnerability allows a remote attacker to bypass certain security restrictions.

The vulnerability exists due to insufficient validation of user-supplied input when processing multiple occurrences of the "@" character in an email address. An application that uses the email module and implements some kind of checks on the From/To headers of a message could be tricked into accepting an email address that should be denied.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Python: 2.7.0 - 2.7.16, 3.5.0 - 3.5.7, 3.6.0 - 3.6.9, 3.7.0 - 3.7.4

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External links
https://bugs.python.org/issue34155
https://github.com/python/cpython/commit/8cb65d1381b027f0b09ee36bfed7f35bb4dec9a9

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.