Grab Text Without WS Regex Misbehaving

[NorthWindH]

xssmeevaluators.js:57

var searchString = grabTextWithOutTrailingWhitespaceRegExp.
            exec(streamListener.attackRunner.testValue.string)[1];

exec is returning null ie not matching. Use trimRight() instead? Potential Fix

Note: FF 3.6/3.0 are hiding error messages. Created highlight branch to force messages to console

[tomaratyn]

Yeah, trimRight seems good... does it also catch \t? Regex's \s has really broad interpretation of whitespace.

[NorthWindH]

Edit: Oh look at that! I reply you in my email and it shows up here as a comment. Nifty.

It should but I'm not certain, I'll check. Let's continue this in the issue
thread.

Cheers,

Hasan Kamal-Al-Deen

On Tue, Dec 13, 2011 at 11:34 AM, Tom Aratyn <
reply@reply.github.com

wrote:

Yeah, trimRight seems good... does it also catch \t? Regex's \s has
really broad interpretation of whitespace.

---

Reply to this email directly or view it on GitHub:
#1 (comment)

[NorthWindH]

Earlier comment not recognizing md syntax. Excuse the spam.

Yes trimRight catches tabs. MDN doesn't give a definition for trimRight but it does define trim as the following function.

if ( !String.prototype.trim ) {
    String.prototype.trim = function() {
        return this.replace( /^\s+|\s+$/g, '' );
    }
}

We can ensure that we have an available trimRight by using the following compatibility function adapted from above:

if ( typeof( String.prototype.trimRight ) === 'undefined' || !String.prototype.trimRight ) {  
  String.prototype.trimRight = function () {  
    return this.replace( /\s+$/, '' );  
  };  
}  

[tomaratyn]

Please don't do this.

Modifying the prototype of global objects is the kind of thing that a) breaks other extensions b) won't pass a review c) is bad manners.

[NorthWindH]

I must admit that I don't entirely understand the issue since we're not stepping on something that already exists and this compatibility code is taken straight from MDN. Would moz really not pass an extension that uses their own compat code? How would it break other extensions that a) are either not programmed to use trimright or b) supplant their own?

In any case, to avoid that road altogether we can:

xssmeTrimRight = function( s ) {
    if ( typeof( String.prototype.trimRight ) === 'undefined' || !String.prototype.trimRight ) {  
        return s.replace( /\s+$/, '' );  
    }

    return s.trimRight();
}