Rejecting requests with significant content length is a good practice to control the network traffic intensity and thus resource consumption in
order to prevent DoS attacks.
Ask Yourself Whether
- size limits are not defined for the different resources of the web application.
- the web application is not protected by rate limiting features.
- the web application infrastructure has limited resources.
There is a risk if you answered yes to any of those questions.
Recommended Secure Coding Practices
- For most of the features of an application, it is recommended to limit the size of requests to:
- lower or equal to 8mb for file uploads.
- lower or equal to 2mb for other requests.
It is recommended to customize the rule with the limit values that correspond to the web application.
Sensitive Code Example
Imports Microsoft.AspNetCore.Mvc
Public Class MyController
Inherits Controller
<HttpPost>
<DisableRequestSizeLimit> ' Sensitive: No size limit
<RequestSizeLimit(10485760)> ' Sensitive: 10485760 B = 10240 KB = 10 MB is more than the recommended limit of 8MB
Public Function PostRequest(Model model) As IActionResult
' ...
End Function
<HttpPost>
<RequestFormLimits(MultipartBodyLengthLimit = 10485760)> ' Sensitive: 10485760 B = 10240 KB = 10 MB is more than the recommended limit of 8MB
Public Function MultipartFormRequest(Model model) As IActionResult
' ...
End Function
End Class
Compliant Solution
Imports Microsoft.AspNetCore.Mvc
Public Class MyController
Inherits Controller
<HttpPost>
<RequestSizeLimit(8388608)> ' Compliant: 8388608 B = 8192 KB = 8 MB
Public Function PostRequest(Model model) As IActionResult
' ...
End Function
<HttpPost>
<RequestFormLimits(MultipartBodyLengthLimit = 8388608)> ' Compliant: 8388608 B = 8192 KB = 8 MB
Public Function MultipartFormRequest(Model model) AS IActionResult
' ...
End Function
End Class
See
