Buffer Overflow Vulnerability

[Reodus]

The provided code (HERE) contains many buffer overflow vulnerabilities due to the unsafe use of sprintf. The function is used to concatenate environment variables with file paths without any bounds checking, which can lead to buffer overflow if the environment variable content exceeds the allocated buffer size. This issue arises because sprintf does not limit the number of characters written to the destination buffer, allowing an attacker to craft an excessively long environment variable that overflows the buffer and potentially overwrites adjacent memory.

This can lead to application crashes, data corruption, or even arbitrary code execution, depending on the nature of the overflow. To mitigate this risk, it is recommended to replace sprintf with snprintf or sprintf_s, which allows specifying a maximum buffer length, preventing unintended memory overwrites. Additionally, ensuring that environment variables are validated and limiting their length before use can further reduce the risk of exploitation.

[toddcarnes]

The spintf function is part of the C standard library. I'm pretty sure that sprintf_s is a Microsoft only thing, The snprintf function, on the other hand, at least has the advantage of also being part of the C standard library. So, it would be a safer choice, but either way you shouldn't change it unless the change is portable across all platforms, especially linux and macOS.

[CruiserOne]

Thank you for the issue report! :) This code in io.cpp (along with similar code in calc.cpp that also reads environment variables) has been updated for the next version.