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
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.057 (92.7th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 93rd percentile — 92.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.057 · newest: 0.057 · change: 0.000
Affected products
- Pyyaml
- Fedoraproject Fedora — versions 28, 29, 30
Weakness classification (CWE)
Public proof-of-concept exploits
References
- github.com/yaml/pyyaml/pull/74 (Patch, Third Party Advisory)
- github.com/yaml/pyyaml/blob/master/CHANGES (Third Party Advisory, Release Notes)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- github.com/marshmallow-code/apispec/issues/278 (Third Party Advisory)
- github.com/yaml/pyyaml/issues/193 (Third Party Advisory)
- github.com/yaml/pyyaml/wiki/PyYAML-yaml.load(input)-Deprecation
- security.gentoo.org/glsa/202003-45 (vendor-advisory, Third Party Advisory)
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.