Better handling of IfExp (ternary) #179
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Reduces false positives. As an example: result = "a" if TAINT else "c" In AST, the assignment value is `IfExp(test=TAINT, body="a", orelse="c")`. Even though `TAINT` is inside the assignment of `result`, it can't actually taint `result` as it is part of the boolean test expression. Previously, `result` would have been tainted, which was a false positive. We don't want to completely ignore the test though in case it contains a sink function. Therefore, if the test contains expressions we transform it as so: result = "a" if b(c) + 2 else "d" to the multi line: __if_exp_0 = b(c) + 2 result = "a" if __if_exp_0 else "d" This way if `b` is a sink and `c` is tainted we see a vulnerability, but even if `c` is tainted we don't taint `result`.
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Reduces false positives.
As an example:
result = "a" if TAINT else "c"In AST, the assignment value is
IfExp(test=TAINT, body="a", orelse="c").Even though
TAINTis inside the assignment ofresult, it can'tactually taint
resultas it is part of the boolean test expression.Previously,
resultwould have been tainted, which was a falsepositive.
We don't want to completely ignore the test though in case it contains a
sink function.
Therefore, if the test contains expressions we transform it as so:
result = "a" if b(c) + 2 else "d"to the multi line:
This way if
bis a sink andcis tainted we see a vulnerability, buteven if
cis tainted we don't taintresult.