SHA (Secure Hash Algorithm) and Keccak functions are generally considered secure, but like all cryptographic algorithms, they are not immune to vulnerabilities, especially when it comes to their implementation. Here are some potential vulnerabilities associated with these functions:

• Implementation Flaws: A recent paper described a vulnerability in several implementations of SHA-3, which is based on the Keccak algorithm. This vulnerability was a buffer overflow that could allow attacker-controlled values to be XORed into memory, potentially leading to the construction of second preimages and preimages for the implementation1.
• Cryptanalytic Advances: While SHA-256 and SHA-3 (Keccak) are currently resistant to known attacks, future advances in cryptanalysis could potentially find weaknesses in these algorithms. This is a common risk for all cryptographic functions as computational power and techniques evolve.
• Side-Channel Attacks: These attacks exploit information gained from the physical implementation of a crypto system, such as timing information, power consumption, electromagnetic leaks, or even sound to break the system. SHA and Keccak could be vulnerable to such attacks if not properly implemented.
• Quantum Computing: Quantum computers have the potential to break many current cryptographic algorithms. SHA-2 and SHA-3 are no exception, as quantum algorithms like Grover’s algorithm could theoretically be used to perform a brute-force search on their hash values more efficiently than classical computers.

It’s important to note that the theoretical vulnerabilities in the cryptographic algorithm itself are different from vulnerabilities in specific implementations. The latter can often be patched or mitigated, while vulnerabilities in the algorithm would require a new cryptographic approach.

https://link.springer.com/chapter/10.1007/978-3-031-30872-7_1