Bug 869819

Summary:	New 'compression attack' backport ready for corner case security matter
Product:	Red Hat Enterprise Linux 6	Reporter:	R P Herrold <herrold>
Component:	httpd	Assignee:	Luboš Uhliarik <luhliari>
Status:	CLOSED WONTFIX	QA Contact:	BaseOS QE - Apps <qe-baseos-apps>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	6.3	CC:	jkaluza, jorton, thoger
Target Milestone:	rc
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2013-12-02 11:24:19 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description R P Herrold 2012-10-24 21:05:39 UTC

Description of problem:

It appears a httpd attack through mod_ssl has been identified, and a fix back-ported upstream into Apache 2.2

Version-Release number of selected component (if applicable):

see: https://issues.apache.org/bugzilla/show_bug.cgi?id=53219

How reproducible:

seen during an audit at: https://www.ssllabs.com/ssltest/analyze.html

Steps to Reproduce:

deploy a unit, updated to current and hardened against 'Beast' and one still gets:

Protocol Details
Secure Renegotiation 	Supported, with client-initiated renegotiation disabled
Insecure Renegotiation 	Not supported
BEAST attack 	Not vulnerable
Compression 	Yes   INSECURE (more info)

with an outlink to:

https://community.qualys.com/blogs/securitylabs/2012/09/14/crime-information-leakage-attack-against-ssltls
  
Actual results:

The noted exception

Expected results:

no exceptions

Additional info:

Comment 4 Tomas Hoger 2012-10-29 13:33:06 UTC

See bug 857051, comment 5 for a way to disable SSL compression in existing httpd versions in Red Hat Enterprise Linux 5 and 6.

Comment 6 Joe Orton 2012-10-29 15:43:49 UTC

There's an ongoing debate on whether or not to change the OpenSSL default on compression.  If this does change, the httpd config option will not be necessary and would work in unexpected ways.  So we are not planning to add this feature to httpd at the current time.

See Tomas's link above for a method to forcibly disable SSL compression support in httpd.

Comment 10 RHEL Program Management 2013-10-14 00:20:18 UTC

This request was evaluated by Red Hat Product Management for
inclusion in the current release of Red Hat Enterprise Linux.
Because the affected component is not scheduled to be updated
in the current release, Red Hat is unable to address this
request at this time.

Red Hat invites you to ask your support representative to
propose this request, if appropriate, in the next release of
Red Hat Enterprise Linux.

Comment 11 Tomas Hoger 2013-11-11 14:54:09 UTC

(In reply to Joe Orton from comment #6)
> There's an ongoing debate on whether or not to change the OpenSSL default on
> compression.

Note that openssl packages in Red Hat Enterprise Linux and Fedora were changed to disable compression by default:

https://rhn.redhat.com/errata/RHSA-2013-0587.html

SSLCompression on does not re-enable compression in httpd/mod_ssl.

Comment 12 Joe Orton 2013-12-02 11:24:19 UTC

Given that the OpenSSL default is now "compression off"... and we have no way to programatically enable SSL/TLS compression via mod_ssl, there does not seem to be any need to add the "SSLCompression" directive any more.