Mercurial > cpython-lru_cache-weakref
diff Lib/string.py @ 6821:b19cd4313126 legacy-trunk
At Barry's suggestion, plug the security leak by using an empty
__builtins__ for all calls to eval(). This still allows someone to
write string.atof("[1]*1000000") (which Jim Fulton worries about) but
effectively disables access to system modules and functions.
| author | Guido van Rossum <guido@python.org> |
|---|---|
| date | Wed, 10 Dec 1997 22:59:55 +0000 |
| parents | 8ef481c7c3af |
| children | 33be7d5d498b |
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--- a/Lib/string.py Wed Dec 10 22:35:02 1997 +0000 +++ b/Lib/string.py Wed Dec 10 22:59:55 1997 +0000 @@ -198,6 +198,9 @@ i = i+1 return r +# "Safe" environment for eval() +safe_env = {"__builtins__": {}} + # Convert string to float re = None def atof(str): @@ -219,7 +222,7 @@ if re and not re.match('[0-9]*(\.[0-9]*)?([eE][-+]?[0-9]+)?$', s): raise ValueError, 'non-float argument to string.atof' try: - return float(eval(sign + s, {})) + return float(eval(sign + s, safe_env)) except SyntaxError: raise ValueError, 'non-float argument to string.atof' @@ -239,7 +242,7 @@ for c in s: if c not in digits: raise ValueError, 'non-integer argument to string.atoi' - return eval(sign + s) + return eval(sign + s, safe_env) # Convert string to long integer def atol(str, base=10): @@ -257,7 +260,7 @@ for c in s: if c not in digits: raise ValueError, 'non-integer argument to string.atol' - return eval(sign + s + 'L') + return eval(sign + s + 'L', safe_env) # Left-justify a string def ljust(s, width):