Use of Inherently Dangerous Function
The program calls a function that can never be guaranteed to work safely.
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.
The following examples help to illustrate the nature of this weakness and describe methods or techniques which can be used to mitigate the risk.
Note that the examples here are by no means exhaustive and any given weakness may have many subtle varieties, each of which may require different detection methods or runtime controls.
The code below calls gets() to read information into a buffer.
The gets() function in C is inherently unsafe.
The code below calls the gets() function to read in data from the command line.
However, gets() is inherently unsafe, because it 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.
Weaknesses in this category are related to the use of built-in functions or external APIs.
Weaknesses in this category are related to the rules and recommendations in the POSIX (POS) section of the SEI CERT C Coding Standard.
This category identifies Software Fault Patterns (SFPs) within the Use of an Improper API cluster (SFP3).
This view (slice) covers all the elements in CWE.
This view (slice) lists weaknesses that can be introduced during implementation.
This view (slice) displays only weakness base elements.