FreeBSD : PyYAML -- arbitrary code execution (c7ec6375-c3cf-11eb-904f-14dae9d5a9d2)

critical Nessus Plugin ID 150230



The remote FreeBSD host is missing one or more security-related updates.


A vulnerability was discovered in the PyYAML library in versions before 5.4, where it is susceptible to arbitrary code execution when it processes untrusted YAML files through the full_load method or with the FullLoader loader. Applications that use the library to process untrusted input may be vulnerable to this flaw. This flaw allows an attacker to execute arbitrary code on the system by abusing the python/object/new constructor. This flaw is due to an incomplete fix for CVE-2020-1747.


Update the affected packages.

See Also

Plugin Details

Severity: Critical

ID: 150230

File Name: freebsd_pkg_c7ec6375c3cf11eb904f14dae9d5a9d2.nasl

Version: 1.4

Type: local

Published: 6/3/2021

Updated: 12/27/2023

Supported Sensors: Nessus

Risk Information


Risk Factor: High

Score: 7.4


Risk Factor: Critical

Base Score: 10

Temporal Score: 7.4

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

CVSS Score Source: CVE-2020-14343


Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.5

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

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:freebsd:freebsd:py36-yaml, p-cpe:/a:freebsd:freebsd:py37-yaml, p-cpe:/a:freebsd:freebsd:py38-yaml, p-cpe:/a:freebsd:freebsd:py39-yaml, cpe:/o:freebsd:freebsd

Required KB Items: Host/local_checks_enabled, Host/FreeBSD/release, Host/FreeBSD/pkg_info

Exploit Ease: No known exploits are available

Patch Publication Date: 6/2/2021

Vulnerability Publication Date: 7/22/2020

Reference Information

CVE: CVE-2020-14343

IAVA: 2021-A-0463