Home/CVE/PyYAML 5.1 through 5.1.2 has insufficient restrictions on the load and load_all functions because of a class deserializa
CVE

CVE-2019-20477

PyYAML 5.1 through 5.1.2 has insufficient restrictions on the load and load_all functions because of a class deserializa

PyYAML 5.1 through 5.1.2 has insufficient restrictions on the load and load_all functions because of a class deserialization issue, e.g., Popen is a class in the subprocess module. NOTE: this issue exists because of an incomplete fix for CVE-2017-18342.

CRITICAL · CVSS 9.8 EPSS 0.00416
Act now
  • Public exploit or PoC is available
  • CVSS base score ≥ 7.0
Sigma rules0 YARA rules0
⬡

Weakness Classification

CWE-502Deserialization of Untrusted Data
▤

Affected Products & Versions

2
pyyaml>= 5.1 and <= 5.1.2
fedoraproject fedoraall versions
▤

Affected Packages

1
Language-ecosystem packages (from OSV) tied to this CVE, with the version that fixes it - the dependency-level detail NVD doesn’t carry.
PyPI pyyaml CRITICAL fixed in 5.2
⚠

Public Exploits & PoCs

1
pocwww.exploit-db.com · 47655www.exploit-db.com
▣

Scoring & Timeline

9.8
CRITICAL · CVSS v3.1 · cve@mitre.org
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD19 Feb 2020 · 04:15 AM
CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
⚑

Vendor Advisories

2
rhsaRHSA-2021:0420Important
rhsaRHSA-2020:4641Moderate
🔗

References & Sources

3
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://github.com/yaml/pyyaml/blob/master/CHANGESRelease NotesThird Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/33VBUY73AA6CTTYL3LRWHNFDULV7PFPN/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/52N5XS73Z5S4ZN7I7R56ICCPCTKCUV4H/
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