Insecure DLL loading in Python

1) Insecure DLL loading

EUVDB-ID: #VU29956

Risk: High

CVSSv4.0: 6.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2020-15523

CWE-ID: CWE-427 - Uncontrolled Search Path Element

Exploit availability: No

Description

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to the "python3X.dll" may use an invalid search path for python3.dll loading (after Py_SetPath has been used). A remote attacker can place a specially crafted Trojan horse python3.dll file, trick the victim into opening a file, associated with the vulnerable application, and execute arbitrary code on victim's system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Python: 3.6.0 - 3.9.0b4

CPE2.3

• cpe:2.3:a:python_org:python:3.6.0:*:*:*:*:*:*:*
• cpe:2.3:a:python_org:python:*:*:*:*:*:*:*:*
• cpe:2.3:a:python_org:python:3.6.2:*:*:*:*:*:*:*
• cpe:2.3:a:python_org:python:3.6.3:*:*:*:*:*:*:*
• cpe:2.3:a:python_org:python:3.6.4:*:*:*:*:*:*:*
• cpe:2.3:a:python_org:python:3.6.5:*:*:*:*:*:*:*
• cpe:2.3:a:python_org:python:3.6.6:*:*:*:*:*:*:*
• cpe:2.3:a:python_org:python:3.6.7:*:*:*:*:*:*:*
• cpe:2.3:a:python_org:python:3.6.8:*:*:*:*:*:*:*
• cpe:2.3:a:python_org:python:3.6.9:*:*:*:*:*:*:*

External links

https://bugs.python.org/issue29778
https://github.com/python/cpython/pull/21297

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.