#VU32881 Infinite loop in Python - CVE-2019-20907

Vulnerability identifier: #VU32881

Vulnerability risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2019-20907

CWE-ID: CWE-835

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 perform a denial of service (DoS) attack.

The vulnerability exists due to infinite loop In Lib/tarfile.py in Python. A remote attacker can create a specially crafted TAR archive leading to an infinite loop when opened by tarfile.open, because _proc_pax lacks header validation.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Python: 3.8.0 - 3.8.3

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External links
https://bugs.python.org/issue39017
https://github.com/python/cpython/pull/21454
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/CAXHCY4V3LPAAJOBCJ26ISZ4NUXQXTUZ/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/VT4AF72TJ2XNIKCR4WEBR7URBJJ4YZRD/
https://usn.ubuntu.com/4428-1/

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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.