Bug 1677536 (CVE-2019-7664)

Summary:	CVE-2019-7664 elfutils: out of bound write in elf_cvt_note in libelf/note_xlate.h
Product:	[Other] Security Response	Reporter:	Dhananjay Arunesh <darunesh>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	abhgupta, apmukher, dbaker, drepper, fche, jakub, jokerman, me, mjw, mjw, sthangav, trankin, twalsh
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2019-08-06 13:21:51 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:	1677537, 1679071, 1679072
Bug Blocks:	1677542

Description Dhananjay Arunesh 2019-02-15 07:46:04 UTC

In elfutils 0.175, a negative-sized memcpy is attempted in elf_cvt_note in
libelf/note_xlate.h because of an incorrect overflow check. Crafted elf input
causes a segmentation fault, leading to denial of service (program crash).

Reference:
https://sourceware.org/bugzilla/show_bug.cgi?id=24084

Comment 1 Dhananjay Arunesh 2019-02-15 07:46:24 UTC

Created elfutils tracking bugs for this issue:

Affects: fedora-all [bug 1677537]

Comment 5 Huzaifa S. Sidhpurwala 2019-02-20 09:58:16 UTC

The vulnerable function was introduced via the following commit:
https://sourceware.org/git/?p=elfutils.git;a=commitdiff;h=c76f0b05676f6207affbfd85e75063db3b6eeccf;hp=cb6d865011ad98a8ac2018f072f396a2268739ca

This was released with elfutils 0.130

Comment 7 Mark Wielaard 2019-02-20 12:39:17 UTC

(In reply to Huzaifa S. Sidhpurwala from comment #5)
> The vulnerable function was introduced via the following commit:
> https://sourceware.org/git/?p=elfutils.git;a=commitdiff;
> h=c76f0b05676f6207affbfd85e75063db3b6eeccf;
> hp=cb6d865011ad98a8ac2018f072f396a2268739ca

That commit introduced elf_cvt_note with a bug that would miss len being smaller than a full header, which was part of elfutils-0.130.
That was fixed in commit 315ebd5288553448406d77b007ff658c1b83abb3 "Fix possible crash in note conversion." which was part of elfutils-0.139.
Then commit 5199e15870e05e5b0b9f98c20fc9b5427aa6dd6a "Recognize and parse GNU Property notes." added support for a new note type with different alignment/padding rules.
This commit (re)introduced the bug by using the wrong constant for the note header length (a corrupt note of 9, 10 or 11 bytes would now possibly trigger the bad memcpy for well chosen namesz and/or descsz values).
This was part of elfutils 0.175, but that commit was (also) backported to elfutils 0.174 for some Fedora and RHEL releases.

Comment 10 Dhananjay Arunesh 2019-02-25 06:15:20 UTC

In reply to comment #9:
> Huzaifa, I hate to quibble, but the "A:H" part in
> cvss3=5.5/CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H seems inflated too. 
> There is no service whose availability is hurt by this bug.  It is an
> ordinary crash-on-crafted-input bug, with no particular security relevance.

Updated A:L and severity to Low

Comment 11 errata-xmlrpc 2019-08-06 12:27:15 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2019:2197 https://access.redhat.com/errata/RHSA-2019:2197

Comment 12 Product Security DevOps Team 2019-08-06 13:21:51 UTC

This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):

https://access.redhat.com/security/cve/cve-2019-7664

Comment 13 errata-xmlrpc 2019-11-05 21:13:46 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2019:3575 https://access.redhat.com/errata/RHSA-2019:3575