Bug 1193442

Summary:	flac: BSS buffer overflow in flac__encode_file()
Product:	[Other] Security Response	Reporter:	Vasyl Kaigorodov <vkaigoro>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED WONTFIX	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	jrusnack, mlichvar
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2015-02-26 09:43:21 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:	1193445
Bug Blocks:	1193444

Description Vasyl Kaigorodov 2015-02-17 10:54:58 UTC

It was reported [1] that in command-line flac encoder/decoder tool, bytes_to_read is not properly checked against the size of ucbuffer, which causes a stack overflow when performing fread in encoding.

Codes related to the crash are in src/flac/encode.c, function flac__encode_file()

PoC file can be found here: http://sourceforge.net/projects/pocfiles/files/libflac_stack.wav/download

[1]: http://sourceforge.net/p/flac/bugs/425/

Comment 1 Vasyl Kaigorodov 2015-02-17 10:57:14 UTC

Created flac tracking bugs for this issue:

Affects: fedora-all [bug 1193445]

Comment 3 Tomas Hoger 2015-02-26 15:45:06 UTC

This is a buffer overflow in flac__encode_file() (in older versions, similar code is in flac__encode_wav() and flac__encode_aif()).  The buffer is static BSS based buffer.  Overflow is caught by FORTIFY_SOURCE which mitigates impact to program abort.  The flaw is in the flac command line tool rather than libFLAC library.

Fixed upstream in:
https://git.xiph.org/?p=flac.git;a=commitdiff;h=c06a44969c1145242a22f75fc8fb2e8b54c55303

Affects the currently latest upstream version 1.3.1.