Bug 1053725 (CVE-2013-1740)

Summary:	CVE-2013-1740 nss: false start PR_Recv information disclosure security issue
Product:	[Other] Security Response	Reporter:	Ratul Gupta <ratulg>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	emaldona, hkario, jkurik, kdudka, kengert, pfrields, rrelyea
Target Milestone:	---	Keywords:	Reopened, Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	nss 3.15.4	Doc Type:	Bug Fix
Doc Text:	A flaw was found in the way TLS False Start was implemented in NSS. An attacker could use this flaw to potentially return unencrypted information from the server.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2014-09-18 03:03:55 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:	1032472, 1054456, 1054457, 1101846, 1113849, 1113853
Bug Blocks:	1054104, 1063682

Description Ratul Gupta 2014-01-15 17:02:25 UTC

A security issue has been reported in NSS, which can be exploited by a malicious user to disclose certain information.

The issue arises due to an error within the "ssl_Do1stHandshake()" function in lib/ssl/sslsecur.c, which can be exploited to potentially return unencrypted and unauthenticated data from PR_Recv. Successful exploitation requires false start to be enabled.

The issue is said to be fixed in NSS 3.15.4.

References:
https://bugs.gentoo.org/show_bug.cgi?id=498172
https://developer.mozilla.org/en-US/docs/NSS/NSS_3.15.4_release_notes

Upstream bug:
https://bugzilla.mozilla.org/show_bug.cgi?id=919877

Patch:
https://bugzilla.mozilla.org/attachment.cgi?id=825813

Comment 1 Ratul Gupta 2014-01-15 17:06:47 UTC

By default, NSS ships with false start disabled, for which the above patch works and was implemented in NSS 3.15.3.

Comment 4 Vincent Danen 2014-01-16 20:53:14 UTC

The upstream bug noted actually has fixes from another upstream bug [1] which notes the actual upstream commit [2], however the next noted commit [3] may also be required.

[1] https://bugzilla.mozilla.org/show_bug.cgi?id=713933
[2] https://hg.mozilla.org/projects/nss/rev/1b9c43d28713
[3] https://hg.mozilla.org/projects/nss/rev/f28426e944ae

Comment 5 Vincent Danen 2014-01-16 21:02:09 UTC

According to this document, False Start has been implemented in NSS since 3.12.9:

https://technotes.googlecode.com/git/falsestart.html

I'm unable to find any corresponding note or changelog for nss to back it up, however.

Comment 7 Vincent Danen 2014-01-16 21:07:05 UTC

Created nss tracking bugs for this issue:

Affects: fedora-all [bug 1054456]

Comment 8 Elio Maldonado Batiz 2014-01-16 21:49:54 UTC

(In reply to Vincent Danen from comment #5)
> According to this document, False Start has been implemented in NSS since
> 3.12.9:
> 
> https://technotes.googlecode.com/git/falsestart.html
> 
> I'm unable to find any corresponding note or changelog for nss to back it
> up, however.

Vincent, Looking at old cvs history (nss switched from cvs to mercurial last year) I see this commit
----------------------------
revision 1.39
date: 2010/07/30 03:00:16;  author: wtc%google.com;  state: Exp;  lines: +12 -1
Bug 525092: Support TLS false start.  The patch is contributed by Adam
Langley of Google <agl>.  r=wtc.
Modified Files:
	cmd/strsclnt/strsclnt.c cmd/tstclnt/tstclnt.c lib/ssl/ssl.h
	lib/ssl/ssl3con.c lib/ssl/ssl3gthr.c lib/ssl/sslimpl.h
	lib/ssl/sslsecur.c lib/ssl/sslsock.c tests/ssl/sslstress.txt
----------------

See https://bugzilla.mozilla.org/show_bug.cgi?id=525092
This may be what you are looking for.

-Elio

Comment 10 Vincent Danen 2014-01-16 22:39:50 UTC

(In reply to Elio Maldonado Batiz from comment #8)
...
> See https://bugzilla.mozilla.org/show_bug.cgi?id=525092
> This may be what you are looking for.

Thanks, Elio.  That's exactly it.  Last comment in that bug is:

"Patch checked in on the NSS trunk (NSS 3.13) and NSS_3_12_BRANCH
(NSS 3.12.8)."

which is pretty close to the 3.12.9 version I had indicated.  Thanks for that confirmation.

Comment 13 Fedora Update System 2014-01-21 05:50:04 UTC

nss-3.15.4-1.fc20, nss-softokn-3.15.4-1.fc20, nss-util-3.15.4-1.fc20 has been pushed to the Fedora 20 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 18 Fedora Update System 2014-02-04 02:46:44 UTC

nss-3.15.4-1.fc19, nss-softokn-3.15.4-1.fc19, nss-util-3.15.4-1.fc19 has been pushed to the Fedora 19 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 19 Huzaifa S. Sidhpurwala 2014-03-10 09:23:41 UTC

Statement:

(none)

Comment 25 errata-xmlrpc 2014-07-22 18:00:23 UTC

This issue has been addressed in following products:

  Red Hat Enterprise Linux 6

Via RHSA-2014:0917 https://rhn.redhat.com/errata/RHSA-2014-0917.html

Comment 26 Martin Prpič 2014-07-28 11:37:01 UTC

IssueDescription:

A flaw was found in the way TLS False Start was implemented in NSS. An attacker could use this flaw to potentially return unencrypted information from the server.

Comment 27 errata-xmlrpc 2014-09-16 05:39:29 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 5

Via RHSA-2014:1246 https://rhn.redhat.com/errata/RHSA-2014-1246.html