I've got some source code that has some cross site scripting vulnerabilities in it. There is no input validation that happens when the browser sends data over to the server which is executing server-side Javascript and classic ASP (IIS 7.0).
My question is, is there a way to override the Request.Form("foo") object/method so that I can call a sanitization function too and get rid of prohibited JS/HTML? I don't want to do a find and replace on every single file everywhere Request.Form is called. I was hoping for something more elegant.
Any suggestions are appreciated.
I don't think you can change Request.Form members.
What you can do, as a partial solution, is to create a code that will run first on every page (for example, using an include directive) which loops over Request.Form, Request.QueryString etc., and if it finds suspected code, it terminates the code execution (Response.End). This solution is partial because it doesn't really sanitize input, it just drops execution when it finds suspected text.
Another option: Create an array, parallel to Request.Form. Populate this array with the same members as in Request.Form, but this time sanitized. Then, quickly do a Find-and-Replace over your whole code base, and change Request.Form to your custom array variable.
There is a way to replace the whole Request object with another COM object but its an insane solution and it would still require that all ASP files that use Form contain a common top include file. Its not possible to replace the Request object or one of its members globally at the application level.
The correct solution to the problem, your statement "don't want to do a find and replace on every single file everywhere" notwithstanding, is to perform such global replace.
Despite the number of .asp files that exist the cost is no more than knocking up a simple program to open each ASP file in a folder tree, adding an include line and replacing Request.Form.
Related
I want to use Blockly to do some calculations, and then generate text files (as opposed to exporting code to JavaScript, Python, PHP, etc.)
I can’t see an obvious way to create my own blocks to do this in Blockly, so using AppInventor (Version: nb168), I got storing and retrieving files to work, in a crude test app on my Android tablet.
In AppInventor/Designer mode, clicking Storage/File creates a “Non-visible component for storing and retrieving files. Use this component to write or read files on your device.”
Then, in AppInventor/Blocks mode, clicking the “File1” icon gives access to 7 “file type blocks”, e.g. AppendToFile, Delete, ReadFrom, SaveFile, etc.
Is it possible to create similar “file type blocks” to use in Blockly Web?
I have limited programming knowledge, so would appreciate simple answers, please.
Thanks, Pete.
Andrew N Marshall from Google/Blockly has told me this:
"This is absolutely possible ...as long as you willing to work within the browser's security restrictions. The resulting files will be need to be manually "downloaded" one at a time, rather than written directly to the user's file system.
... I would start understanding what JavaScript functions are available to you. Attempt to construct a string and save it via a download dialog...
That means the "file" contents are really just a string in memory, a JavaScript variable. We have lots of "Text" blocks that can do a variety of operations on strings. If those are enough, you'll only need one new block to identify the string variable and initiate the download process.
Otherwise, you'll need to think about what blocks you want, and how they operate. They may operate on a specific variable in the JavaScript VM, not necessary exposed as a variable to Blockly.
Either way, you'll need to learn how to create a block and a Blockly app. We have a code lab that will walk you through all the steps. You'll learn how each block generates a string of code, and in your case, that code will be related to the download code I mentioned earlier."
So I'll press on - I just wanted to be sure my goal is actually achievable before I started.
Thanks, Pete.
I have created/recorded a script in Vugen, however the the URL of the site has been changed recently. Is there any way just by replacing the url with a parameter works?
I have tried by replacing url with parameters, the new URL is
http://xsx.xxx.xsx.xxx/test99
Yhe parameters I have tried are below:
NewUrl: http://xsx.xxx.xsx.xxx/
Newhos: test99
I have replaced all in the script and when I run it I get the following error:
Error -27651: Attempted read from an unconnected socket (empty response, no HTTP headers received). URL="http://xsx.xxx.xsx.xxx/scripts/uiServer.dll"
What is the solution for this? Should i record again with the new URL ?
Thanks.
Hope I've understood what you're asking for, so here goes. If it's only the URL that has changed and not the content of the site which you might require later on in your script that this is fairly simple to do.
As you have created the new parameters ensure that they are getting the data from the same DAT file. I.e. newurl.dat which contains the following:
newurl,newhost
http://xsx.xxx.xsx.xxx/,test99
and assign the parameters to the correct column and have the newhost set to sameline as newurl. This way it’s easier to maintain I believe.
Now that the parameters have been created and properly assigned in your script you’ll need to change the url your trying to change from:
http://xsx.xxx.xsx.xxx/oldtest to {newurl}{newhost}
this needs to be done for all instances where the change has occurred.
Hope this helps with your problem you’re having.
Are you certain that the build level has not also changed at the same time as the host? If so then your new instance may be out of synch with the request model of the scripts built using an earlier build. Developers have a habit of including items below the scenes that do affect the site visually but change the structure of the requests. The error you are receiving is common when you attempt to continue a conversation on a dead connection resulting from a missed dynamic session component which may have been added in the last build.
When in doubt quickly record the second site and take a look at the differences in the requests, even to the point of using WinDiff (included in LoadRunner) for this purpose.
I'm developing a webapp that will need to download the html form a website and then iterate through the code and try to find a specific but ever changing value (in our case it will be the price for the product).
For this, I was thinking about asking the user (upon installation and setup) to provide the system with a few lines of html from the page (that has the price) and then from then on, every time we need to fetch the price we would try to search for those lines and find the price.
Now, I believe this is a horrible and slow way of doing this and since there are no rules and the html can be totally different from one website to another (even the same website might change) I couldn't find a better way.
One improvement that I thought about was to iterate through the first time and record the line at which we find the code. Once found, the subsequent times we would then start from a few lines before the expected location and start the search. Any Thoughts on how I can improve on this?
I posted this question on https://cstheory.stackexchange.com/ but they commented that it's not on topic and that I should post it here.
I have the code for the above and if needed I can post it, I'm simply thinking that there must be a better, faster way of doing this.
This is actually something I tried for a project recently (using BeautifulSoup and Python). The solution that worked for me was to workout CSS selectors (which can map to jQuery selectors) that targeted the elements that contained the values I was looking for. In my case I was able to narrow down the full document to just the elements that contained what I was looking for but if you couldn't get exactly what you where after you could combine this with some extra lactic like test to see if it looks like a price (via regex) or test what it is next to.
I am working on a language service and would like the parsing after the user types code to be faster.
Right now I rely on the ParseReason.Check and OnIdle mechanism that's documented on MSDN, but its often called a long time after the user has typed code. Sometimes it helps to move the cursor to another line to trigger it faster.
What I'd like to do is to force parse the file after I detect the user has typed in the file. I'm able to detect when the user is typing, but I don't know how to trigger the parser with a ParseRequest.
I was running into a similar problem, I wanted to scan files not opened in VS. The best I could do was to abstract out my parse functionality so it gets called by VS, but also called by another internal function to my extension whenever I desired without going through VS, and this would store my parse results to the same structures as the direct VS call on ParseRequest.
I'd be curious to know if you find a better way of doing it though.
You could try calling BeginParse() on your Source implementation. That creates a ParseRequest with the Check parse reason. I turned off the OnIdle timer in my language service and tested it out and it appears to work.
If your code that detects user key-presses has access to an instance of your LanguageService implementation, then you can use service.GetSource(...).BeginParse(). If it has access to the Source itself, then it's even easier.
I am trying to build a part of a website which takes in a text passage as input, and outputs the same text passage, except with the definition of each word appearing when the user rolls over (or clicks) any given word. I have a pre-made .exe file which maps input words to their definitions (takes in words from standard input and outputs the definition to standard output).
My problem, then, is to run user input through the .exe file on the website's server, then put the output back onto the page. It seems like a fairly trivial problem, but I have no idea where to start.
So my questions are: is this project even possible? If so, what languages/tools do I need to be able to use in order to implement it? Are there keywords that describe what I'm talking about that I could use to look up tutorials/solutions on the Web?
I have rudimentary knowledge of PHP, HTML, and Javascript, but so little experience that I can't judge whether (and how) they can be used to approach this problem.
Note: I do not have access to the .exe source, so I must use the .exe itself as my input-output mechanism.
With AJAX and PHP, you can do accomplish this with minimal effort.
JavaScript's AJAX features would send the word you input to the PHP page, and from the PHP page, you can run the external exe file with the sent word as an argument (sanitize it, please. People can inject code which will explode your servers!):
<?php
$word = $_POST['input_word']; // MAKE SURE YOU SANITIZE THIS. If you don't, system security goes down the toilet.
exec('myprogram.exe ' + $word, $output_array);
print_r($output_array);
?>