Insecure Direct Object References

Insecure Direct Object References #

Insecure Direct Object References occur when an application provides direct access to objects based on user-supplied input. As a result of this vulnerability attackers can bypass authorization and access resources in the system directly, for example database records or files. - OWASP

Tools #

Exploit #

The value of a parameter is used directly to retrieve a database record.

http://foo.bar/somepage?invoice=12345

The value of a parameter is used directly to perform an operation in the system

http://foo.bar/changepassword?user=someuser

The value of a parameter is used directly to retrieve a file system resource

http://foo.bar/showImage?img=img00011

The value of a parameter is used directly to access application functionality

http://foo.bar/accessPage?menuitem=12

IDOR Tips #

Change the HTTP request: POST → PUT
Change the content type: XML → JSON
Increment/decrement numerical values (1,2,3,..)
GUID/UUID might be weak
Transform numerical values to arrays: {"id":19} → {"id":[19]}

Examples #

Labs #

Insecure direct object references