Reduce risk of XSS #1051
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Reduce risk of XSS #1051
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Rob--W
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Use `Object.keys` instead of a for-in loop to find optional attributes. The former only grabs keys that are own properties, the latter also includes inherit properties from `Object.prototype`. This reduces the risk of XSS if an attacker somehow manages to manipulate the prototype chain of the Object prototype.
If an attacker has control over the values of the attributes "data-prompt", "data-user", or "data-host", then XSS was possible. This fixes the issue, by encoding quotes as the `"` entity.
There is no need for `innerHTML` here. At best nothing happens, at worst XSS is possible (though the odds are negligible since the attacker would have to control the detected language).
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Prism and its plugins sometimes mixes potentially unsafe input with HTML. In the worst case, this may lead to a XSS vulnerabilities, especially when prism is used to highlight external code.
See the individual commits for the fixes. If you decide to merge them all, don't squash the commits as doing so may obscure the relation between the commit message and the fix.