prevent JavaScript injection with setValue()#30
prevent JavaScript injection with setValue()#30vt512 wants to merge 1 commit intovaadin-component-factory:v24from
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It is a bad idea to concatenate a JavaScript expression with a value that may be from a user input.
The call of
autocommit.setValue("xy\");alert(\"Hello World!");
leads to the alert window shown in the browser.
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It appears to me that there is no functional difference between the old code and the new. That said, this is a real issue; a proper fix would be to sanitize the input string using e.g. JSoup. |
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I had tested the two versions executeJs and callJsFunction. With callJsFunction the alert was not displayed. callJsFunction does only concatenate the functionName and calls scheduleJavaScriptInvocation() with the expression "return $0._setValue($1)". This is packed together with an array of the parameters (the value) to the client side. I don't see a string concatenation of the value. That means: I don't think that sanitization is needed. Just exchange executeJs with callJsFunction and it is fine. |
2 participants
It is a bad idea to concatenate a JavaScript expression with a value that may be from a user input. The call of
autocommit.setValue("xy");alert("Hello World!"); leads to the alert window shown in the browser.