title: Applicure dotDefender WAF format string vulnerability
product: dotDefender for Linux/Apache
dotDefender is a web application security solution (a Web Application
Firewall, or WAF) that offers strong, proactive security for your websites and
web applications.
URL: http://www.applicure.com/Products/dotdefender
dotDefender displays an error page when blocking an attack. The error page is
generated from a template which can contain various template variables. These
variables are expanded into a buffer first, the result of which is then passed
to AP_PRINTF() without checking for format string identifiers. Any remaining
format strings are interpreted by AP_PRINTF(), allowing for a format string
injection attack.
This is immediately exploitable by an unauthenticated attacker if the <%IP%>
template tag is used in the error page (not the case in the default template).
In this case an attacker can inject format strings in the "Host"-header. Other
attack vectors may exist if the attacker manages to access the dotDefender web
interface which requires a password.
Successful exploitation allows an attacker to execute arbitrary code on the
server.
No proof-of-concept exploit will be released.
The vulnerability has been tested with dotDefender 4.26 for Linux/Apache.
dotDefender for Windows is not affected.
2012-10-17: Contacted vendor
2012-11: Fixed version is released
2012-11-15: SEC Consult releases security advisory
Upgrade to at least version 5.00 of dotDefender for Linux:
http://www.applicure.com/download-latest
https://www.sec-consult.com/en/Vulnerability-Lab/Advisories.htm
The SEC Consult Group
Office Vienna
Mooslackengasse 17
A-1190 Vienna
Austria
Tel.: +43 / 1 / 890 30 43 - 0
Fax.: +43 / 1 / 890 30 43 - 25
Mail: research at sec-consult dot com
www.sec-consult.com
Office Singapore
4 Battery Road
#25-01 Bank of China Building
Singapore (049908)
Mail: office at sec-consult dot sg
Check out our blog at:
http://blog.sec-consult.com/
And this thing here:
http://wordpress.org/extend/plugins/mvis-security-center/
EOF B. Mueller / November 2012