FreeBSD VuXML: Documenting security issues in FreeBSD and the FreeBSD Ports Collection

PyYAML -- arbitrary code execution

Affected packages
py36-yaml < 5.4
py37-yaml < 5.4
py38-yaml < 5.4
py39-yaml < 5.4

Details

VuXML ID c7ec6375-c3cf-11eb-904f-14dae9d5a9d2
Discovery 2020-07-22
Entry 2021-06-02

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.

References

CVE Name CVE-2020-14343
URL https://access.redhat.com/security/cve/CVE-2020-14343
URL https://bugzilla.redhat.com/show_bug.cgi?id=1860466
URL https://github.com/yaml/pyyaml/issues/420