Deserialization in Pyyaml

CVE-2017-18342

In PyYAML before 5.1, the yaml.load() API could execute arbitrary code if used with untrusted data. The load() function has been deprecated in version 5.1 and the 'UnsafeLoader' has been introduced for backward compatibility with the function.

Vulnerability class: Insecure Deserialization

EPSS: 0.056 (92.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2017-18342?
CVE-2017-18342 is a critical-severity vulnerability in Pyyaml, classified under Deserialization of Untrusted Data. CVSS score: 9.8/10. Published 2018-06-27.
How severe is CVE-2017-18342?
Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2017-18342 known to be exploited?
24 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.