Re: An Alternate View of Recently Reported PHP Vulnerabilities

[dullien () gmx de]

Hey Steven , all,

SMC> How many people who audit PHP applications verify that the second
SMC> argument to str_repeat() is valid?

Nobody, because the misbehaviour of this given function is a _bug_ and
thus not documented. Without documenting the valid input ranges, there
can be no "validation", only "guessing that this is now valid".

SMC> How many otherwise innocent functions in PHP can have unexpected
SMC> results if an attacker can control one of the parameters?

Expect the same to hold true for almost any other language. The libc's
these days are relatively "bug-free", but the libraries of PHP etc.
have not undergone the same amount of auditing.

SMC> And maybe entire classes of vulnerabilities that are assumed to be
SMC> specific to a particular language, aren't.

Any vulnerability existing in C is very likely going to occur in other
languages which (in the end) chain down to C-like code.

Cheers,
dullien
PS: Let us please just keep the entire Java discussion out of this :)


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