Bug 1877780

Summary:	CVE-2020-24980 bison: Assertion failure in src/parse-gram.c could result in DoS [fedora-all]
Product:	[Fedora] Fedora	Reporter:	Michael Kaplan <mkaplan>
Component:	bison	Assignee:	Arjun Shankar <ashankar>
Status:	CLOSED NOTABUG	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	medium	Docs Contact:
Priority:	medium
Version:	32	CC:	arjun.is, ashankar, me, pfrankli
Target Milestone:	---	Keywords:	Security, SecurityTracking
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	No Doc Update
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2020-09-25 17:16:12 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:
Bug Blocks:	1877779

Description Michael Kaplan 2020-09-10 12:24:34 UTC

This is an automatically created tracking bug!  It was created to ensure
that one or more security vulnerabilities are fixed in affected versions
of fedora-all.

For comments that are specific to the vulnerability please use bugs filed
against the "Security Response" product referenced in the "Blocks" field.

For more information see:
http://fedoraproject.org/wiki/Security/TrackingBugs

When submitting as an update, use the fedpkg template provided in the next
comment(s).  This will include the bug IDs of this tracking bug as well as
the relevant top-level CVE bugs.

Please also mention the CVE IDs being fixed in the RPM changelog and the
fedpkg commit message.

NOTE: this issue affects multiple supported versions of Fedora. While only
one tracking bug has been filed, please correct all affected versions at
the same time.  If you need to fix the versions independent of each other,
you may clone this bug as appropriate.

Comment 1 Michael Kaplan 2020-09-10 12:24:37 UTC

Use the following template to for the 'fedpkg update' request to submit an
update for this issue as it contains the top-level parent bug(s) as well as
this tracking bug.  This will ensure that all associated bugs get updated
when new packages are pushed to stable.

=====

# bugfix, security, enhancement, newpackage (required)
type=security

# low, medium, high, urgent (required)
severity=medium

# testing, stable
request=testing

# Bug numbers: 1234,9876
bugs=1877779,1877780

# Description of your update
notes=Security fix for [PUT CVEs HERE]

# Enable request automation based on the stable/unstable karma thresholds
autokarma=True
stable_karma=3
unstable_karma=-3

# Automatically close bugs when this marked as stable
close_bugs=True

# Suggest that users restart after update
suggest_reboot=False

======

Additionally, you may opt to use the bodhi web interface to submit updates:

https://bodhi.fedoraproject.org/updates/new

Comment 2 Arjun Shankar 2020-09-25 17:16:12 UTC

While this is a bug and has been fixed [1] in bison-3.7.2 (already in rawhide), it is not a valid CVE:
https://nvd.nist.gov/vuln/detail/CVE-2020-24979

I'm closing this as NOTABUG because this is associated with an invalid CVE-ID (one that has been rejected
as not having security implication).

Either way, it's fixed in rawhide via 3.7.2, so there is no necessary fix.

It is not worth fixing this in earlier versions of Fedora because a crash in bison because of
deliberately invalid input does not have runtime implications.

[1] https://github.com/akimd/bison/commit/b7aab2dbad43aaf14eebe78d54aafa245a000988

Comment 3 Arjun Shankar 2020-09-25 17:17:50 UTC

Correction:

I used an incorrect CVE ID in my above comment, but the reasoning still stands.

Correct one is: https://nvd.nist.gov/vuln/detail/CVE-2020-24980