Bug 2545820 (CVE-2017-20285)

Summary: CVE-2017-20285 perl-yaml: perl-yaml: Arbitrary destructor method execution via crafted YAML document
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in perl-yaml. An attacker can trigger unintended actions, such as arbitrary file deletion, by supplying a specially crafted YAML document. The parser permits untrusted documents to instantiate arbitrary object classes, causing Perl to automatically execute their destructor methods when the objects are cleaned up.
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Description OSIDB Bzimport 2026-10-05 07:11:50 UTC 
YAML versions before 1.30 for Perl allow a loaded document to trigger the DESTROY method of arbitrary classes.

A perl/hash:Class tag blesses a hash into the class it names. The document supplies the object's fields, and Perl calls DESTROY when it goes out of scope.

What DESTROY does depends on the classes the process has loaded. With File::Temp::Dir from core Perl, it can delete a directory tree the document names.