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CWE-242: Use of Inherently Dangerous Function
Description Summary The program calls a function that can never be guaranteed to work safely.
Extended Description Certain functions behave in dangerous ways regardless of how they are used. Functions in this category were often implemented without taking security concerns into account. The gets() function is unsafe because it does not perform bounds checking on the size of its input. An attacker can easily send arbitrarily-sized input to gets() and overflow the destination buffer. Similarly, the >> operator is unsafe to use when reading into a statically-allocated character array because it does not perform bounds checking on the size of its input. An attacker can easily send arbitrarily-sized input to the >> operator and overflow the destination buffer. Example 1 The excerpt below calls the gets() function in C, which is inherently unsafe. (Bad Code) Example
Language: C char buf[BUFSIZE]; gets(buf); Example 2 The excerpt below calls the gets() function in C, which is inherently unsafe. (Bad Code) Example
Language: C char buf[24];
printf("Please enter your name and press
<Enter>\n");
gets(buf);
...
} However, the programmer uses the function gets() which is inherently unsafe because it blindly copies all input from STDIN to the buffer without checking size. This allows the user to provide a string that is larger than the buffer size, resulting in an overflow condition.
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Page Last Updated:
February 20, 2013
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