Dynamic linking can cause security concerns because the path for searching dynamic libraries is not known till runtime.

Dynamic linking is a process in which the necessary libraries or modules required by a program are linked at runtime rather than at compile time. This allows for flexibility and reusability of code, as multiple programs can share the same libraries. However, this flexibility can also introduce security concerns.

1. Runtime path determination:
One of the main reasons why dynamic linking can cause security concerns is that the path for searching dynamic libraries is not known until runtime. When a program is executed, it searches for the required libraries in specific directories or paths specified in the system's environment variables. This means that the exact location of the libraries is determined dynamically, making it difficult to predict or control.

2. Malicious code injection:
Since the exact location of the dynamic libraries is not known until runtime, it opens up the possibility of malicious code injection. Attackers can exploit this by placing a malicious library with the same name as a legitimate one in a directory that is searched before the legitimate location. When the program is executed, it unknowingly loads the malicious library instead of the intended one, potentially leading to unauthorized access, data breaches, or other security vulnerabilities.

3. Dependency hijacking:
Dynamic linking also introduces the risk of dependency hijacking. If a program relies on a specific version of a library, an attacker can replace that library with a different version that contains vulnerabilities or malicious code. When the program is executed, it may load the compromised library, resulting in security issues.

4. Lack of cryptographic procedures:
Another reason why dynamic linking can be a security concern is the lack of cryptographic procedures. When a program is statically linked, the integrity and authenticity of the libraries can be verified using cryptographic techniques. However, in dynamic linking, this verification is not possible because the libraries are loaded at runtime. This leaves the program vulnerable to tampering or substitution of libraries.

Conclusion:
In conclusion, dynamic linking can cause security concerns primarily due to the unknown runtime path determination of libraries. This can lead to malicious code injection, dependency hijacking, and a lack of cryptographic procedures. To mitigate these risks, it is essential to implement proper security measures such as validating library paths, using secure coding practices, and performing integrity checks on dynamically loaded libraries.