Bug 1793930 (CVE-2019-20393)

Summary:	CVE-2019-20393 libyang: double-free in function yyparse() when empty description is used
Product:	[Other] Security Response	Reporter:	Riccardo Schirone <rschiron>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	mruprich, tkorbar
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	libyang 1.0-r1	Doc Type:	If docs needed, set a value
Doc Text:	A double-free flaw occurs in libyang in function yyparse() when an empty description is used. Applications that use libyang to process untrusted input YANG files may be vulnerable to this flaw, possibly causing a crash or potential code execution.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2021-10-28 10:10:33 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1797541, 1797619, 1910046
Bug Blocks:	1790579

Description Riccardo Schirone 2020-01-22 09:55:45 UTC

A double-free is present in libyang up to version v1.0-r1 in function yyparse() when an empty description is used. Applications that use libyang to parse untrusted input yang files may be vulnerable to this flaw, which would cause a crash or potentially code execution.

Upstream issue:
https://github.com/CESNET/libyang/issues/742

Upstream fix:
https://github.com/CESNET/libyang/commit/d9feacc4a590d35dbc1af21caf9080008b4450ed

Comment 1 Riccardo Schirone 2020-02-03 11:36:47 UTC

Created libyang tracking bugs for this issue:

Affects: fedora-all [bug 1797541]