Buffer overflow from unbounded string input

The string copy function is used to copy a string of characters to a buffer of memory. The strcpy function has no argument to limit the size of the written data, so a buffer overflow may result.

The SV.UNBOUND_STRING_INPUT.CIN checker looks for code calling string copy functions that don't specify a buffer size-either getwd() or a function that uses C++ input.

Vulnerability and risk

If the string copy function is called without a size parameter, a buffer overrun error can result. This can lead to application instability or, with a carefully constructed attack, code injection, or other vulnerabilities.

Mitigation and prevention

To avoid this vulnerability, make sure you use functions that have buffer size as an input parameter, or use a function like strlen() to determine the buffer size you need.

Related checkers

Security training

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