David Litchfield
25/01/06, 19:45
There's a critical flaw in the Oracle PLSQL Gateway, a component of iAS, OAS
and the Oracle HTTP Server, that allows attackers to bypass the
PLSQLExclusion list and gain access to "excluded" packages and procedures.
This can be exploited by an attacker to gain full DBA control of the backend
database server through the web server.
This flaw was reported to Oracle on the 26th of October 2005. On November
the 7th NGS alerted NISCC (http://www.niscc.gov.uk) to the problem. It was
hoped that due to the severity of the problem that Oracle would release a
fix or a workaround for this in the January 2006 Critical Patch Update. They
failed to do so.
The workaround is trivial; using mod_rewrite, which is compiled into
Oracle's Apache distribution it is possible to stop the attack. The
workaround checks a user's web request for the presence of a right facing
bracket, ')'.
Add the following four lines to your http.conf file then stop and restart
the web server
RewriteEngine on
RewriteCond %{QUERY_STRING} ^.*\).*|.*%29.*$
RewriteRule ^.*$ http://127.0.0.1/denied.htm?attempted-attack
RewriteRule ^.*\).*|.*%29.*$ http://127.0.0.1/denied.htm?attempted-attack
I don't think leaving their customers vulnerable for another 3 months (or
perhaps even longer) until the next CPU is reasonable especially when this
bug is so easy to fix and easy to workaround. Again, I urge all Oracle
customers to get on the 'phone to Oracle and demand the respect you paid
for.
Cheers,
David Litchfield
and the Oracle HTTP Server, that allows attackers to bypass the
PLSQLExclusion list and gain access to "excluded" packages and procedures.
This can be exploited by an attacker to gain full DBA control of the backend
database server through the web server.
This flaw was reported to Oracle on the 26th of October 2005. On November
the 7th NGS alerted NISCC (http://www.niscc.gov.uk) to the problem. It was
hoped that due to the severity of the problem that Oracle would release a
fix or a workaround for this in the January 2006 Critical Patch Update. They
failed to do so.
The workaround is trivial; using mod_rewrite, which is compiled into
Oracle's Apache distribution it is possible to stop the attack. The
workaround checks a user's web request for the presence of a right facing
bracket, ')'.
Add the following four lines to your http.conf file then stop and restart
the web server
RewriteEngine on
RewriteCond %{QUERY_STRING} ^.*\).*|.*%29.*$
RewriteRule ^.*$ http://127.0.0.1/denied.htm?attempted-attack
RewriteRule ^.*\).*|.*%29.*$ http://127.0.0.1/denied.htm?attempted-attack
I don't think leaving their customers vulnerable for another 3 months (or
perhaps even longer) until the next CPU is reasonable especially when this
bug is so easy to fix and easy to workaround. Again, I urge all Oracle
customers to get on the 'phone to Oracle and demand the respect you paid
for.
Cheers,
David Litchfield