If not redirected, please click here https://www.thesecuritybuddy.com/vulnerabilities/what-is-confused-deputy-problem/
What is Confused Deputy Attack ?
Let's look at a simple example first to
understand what Confused Deputy Attack is.
Suppose, a client sends name of an
input file and output file to the server. The server compiles the
input file and stores it in the output file. Let's also assume that,
the client has less privilege than the server.
Now, also assume there is another file
“restricted” on which the server has permission where the client
does not. At this point, if the client sends an arbitrary input file
and “restricted” as output file, the server will compile the
input file and write it to the file “restricted”, overwriting its
previous content. Here, the client did not have permission to
“restricted”, but server had. So, the server here is a deputy who
was exploited to perform a malicious action. This type of problems
are called Confused Deputy Attack.
Are there any real life examples of Confused Deputy Attack ?
There are a number of examples of Confused Deputy Attack.
- Cross-site request forgery is an example of Confused Deputy Attack. Web applications normally use a cookie to authenticate all requests transmitted by a browser. An attacker can take advantage of that and use JavaScript to submit an authenticated HTTP request using authority of the client of the web browser.
- Clickjacking is another example of Confused Deputy Attack. A user visits an attacker controlled website and thinks he is harmlessly browsing a website. But actually, he is tricked to act as a confused deputy and performs sensitive actions to get infected by malware.
- FTP Bounce Attack is an example of Confused Deputy Attack. In this attack, an attacker uses PORT command and uses a victim machine's FTP Server to get access to TCP ports to which the attacker himself has to permission to connect to. Here, the FTP Server is the confused deputy.
How to prevent Confused Deputy Attack ?
Yes, the client can send the input file
and capability of the output file to the server, where a capability
of a file is the name of the file, along with permission on the file
of the client. As a result, if the client does not have permission on
the output file, it won't be able to overwrite it.
In the example of Cross-site request
forgery, a URL supplied cross site would use its own authority
irrespective of the authority of the client of the web browser.
This was an informative article on
Confused Deputy Attack. Hope you liked it.
No comments:
Post a Comment