Red Hat Bugzilla – Bug 869819
New 'compression attack' backport ready for corner case security matter
Last modified: 2013-12-02 08:03:22 EST
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):
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:
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:
The noted exception
See bug 857051, comment 5 for a way to disable SSL compression in existing httpd versions in Red Hat Enterprise Linux 5 and 6.
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.
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.
(In reply to Joe Orton from comment #6)
> There's an ongoing debate on whether or not to change the OpenSSL default on
Note that openssl packages in Red Hat Enterprise Linux and Fedora were changed to disable compression by default:
SSLCompression on does not re-enable compression in httpd/mod_ssl.
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.