• Fuzzing over HTTP
• Injecting faults with various set of payload
• Try to raise the exception
• Exception throw message back as part of HTTP
• Scanning response for signatures
• If signature found, it becomes interesting
entry for exploitation
• Errors can send information about technology stack and
weaknesses. In some cases error helps in fingerprinting web
and application servers running on target application.
• Internal IP addresses and architecture layout for network.
• Intranet applications and their setups.
• Type of backend database and its connection information.
• Internal folders and file system layout for application.
• Username and authentication mechanism and disclosures.
• Hidden paths and folder which helps in retrieving several
other files and internal database information.
• Error code and other relevant information which helps in
analyzing possible cause for an attacker.
• Deployment cause – Application runs on technology stack,
it involves web server, application servers, plugins and
handlers, database server etc. If these components are not
configured properly or having inherent vulnerability then it
can lead to information disclosure.
• Source code cause – If application source code is not having
best practices for error or exception handling then it ends
up leaking information to end client as part of business
logic. This set of information can help in detecting
vulnerability or end up sharing internal logic information.
File not found errors
• HTTP 404 - not found
Internal server errors
• HTTP 500 error messages:
PHP error example
• Attempting to read a file which does not exist:
Application error message example
• Attempting to place an order that already
MySQL error example
• Generated from a failed PHP MySQL query:
MS-SQL error example
• Generated from a failed ASP MS-SQL query: