Apache

CVE-2009-3555 – apache/mod_ssl vulnerability and mitigation

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Subject: CVE-2009-3555 - apache/mod_ssl vulnerability and mitigation

Apache httpd is affected by CVE-2009-3555[1] (The SSL Injection 
or MiM attack[2]).

The Apache httpd webserver relies on OpenSSL for the implementation of 
the SSL/TLS protocol.

We strongly urge you to upgrade to OpenSSL 0.9.8l; and to be prepared 
to deploy OpenSSL 0.9.8m as it becomes available[3]. 

Note that these are for short term and mid-term mitigation only; the 
long term solution may well require a modification of the SSL and/or 
TLS protocols[4].

For those who are not able to upgrade OpenSSL swiftly and/or for 
those who need detailed logging - we recommend that you roll out 
this patch[5]:

  http://www.apache.org/dist/httpd/patches/
       apply_to_2.2.14 CVE-2009-3555-2.2.patch
 sha1: 28cd58f3758f1add39417333825b9d854f4f5f43

as soon as possible. This is a partial fix in lieu of the protocol 
issues being addressed and further changes to OpenSSL. Like the 
OpenSSL 0.9.8l stopgap measure this patch rejects 
in-session renegotiation.

If you are unable to patch and unable to roll our a newer version of 
OpenSSL, and you rely on Client Side Authentication with Certificates 
then we recommend that you 1) ensure that you limit your configuration 
to a single 'SSLClient require' on VirtualHost/Sever level and 2) 
remove all other (re)negotiation/require directives. However this does 
NOT fully protect you - it just curtails authentication in this 
specific setting.



1: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2009-3555
2: http://www.links.org/?p=780, http://extendedsubset.com/?p=8
3: http://www.openssl.org/source/
   openssl-announce mailing list on
   http://www.openssl.org/support/community.html
4: http://www.ietf.org/mail-archive/web/tls/current/msg03963.html
5: svn diff -r833581:833594 https://svn.apache.org/repos/asf/
   httpd/httpd/trunk/modules/ssl 

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