Bug 1484823 (CVE-2017-12966)

Summary:	CVE-2017-12966 asn1c: segmentation fault in asn1f_lookup_symbol_impl function
Product:	[Other] Security Response	Reporter:	Adam Mariš <amaris>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED UPSTREAM	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	npmccallum, rharwood
Target Milestone:	---	Keywords:	Reopened, Security
Target Release:	---
Hardware:	All
OS:	Linux
URL:	https://github.com/vlm/asn1c/issues/190
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2019-06-08 03:22:07 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:	1484824
Bug Blocks:

Description Adam Mariš 2017-08-24 11:24:12 UTC

The asn1f_lookup_symbol_impl function in asn1fix_retrieve.c in
libasn1fix.a in asn1c 0.9.28 allows remote attackers to cause a denial
of service (segmentation fault) via a crafted .asn1 file.

Reference:

https://drive.google.com/open?id=0B9DojFnTUSNGd05zSHI1RmpKQjQ

Comment 1 Adam Mariš 2017-08-24 11:24:35 UTC

Created asn1c tracking bugs for this issue:

Affects: fedora-all [bug 1484824]

Comment 2 Robbie Harwood 2017-08-24 16:35:12 UTC

This has got to be one of the worst upstream bug reports I've ever seen.

- There's no traceback or indication of what actually went wrong, just "access violation" and the function.
- There's no reproducer; in the middle, the reporter shows a different file.  It is not clear why this file is shown.
- The reporter has clearly made a custom build (probably for fuzzing), but couldn't be bothered to build it unoptimized.
- asn1c is expressly not intended to be public facing; no compiler is hardened in this manner.

Given the above, I'm kind of shocked that this was issued a CVE, and I doubt anyone will be "fixing" it soon.

Comment 3 Robbie Harwood 2017-08-24 16:36:10 UTC

(Sorry, applied status change to the wrong bug instead of the Fedora one.)

Comment 4 Product Security DevOps Team 2019-06-08 03:22:07 UTC

This CVE Bugzilla entry is for community support informational purposes only as it does not affect a package in a commercially supported Red Hat product. Refer to the dependent bugs for status of those individual community products.