Insecure hashes are cryptographic hash functions that are vulnerableto attacks that can compromise the integrity and authenticity of data.Cryptographic hashes are widely used in security systems to ensure theintegrity of data, such as passwords or digital signatures, by generatinga fixed-length output that represents the original data.
Insecure hashes can be exploited by attackers to manipulate the originaldata without being detected, resulting in significant security vulnerabilities.
Examples of insecure hashes include the Message Digest 5 (MD5) andSecure Hash Algorithm 1 (SHA-1), which are vulnerable to collision attacks.A collision attack is an attack where an attacker can generate two differentpieces of data that have the same hash value, which can be used to substituteone piece of data for another, without being detected.
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What is the impact of insecure hashes?
Insecure hashes in security systems have significant impacts on the securityand privacy of data. Here are some of the potential impacts:
- Data breaches: Insecure hashes can result in vulnerabilities that can be exploited by attackers to gain unauthorized access to sensitive data.
- Information disclosure: Insecure hashes can also result in vulnerabilities that allow attackers to manipulate and forge data, which can result in information disclosure and impersonation.
- Malicious attacks: Attackers can use insecure hashes to launch various types of attacks, such as collision attacks or dictionary attacks, which can be used to break weak or outdated hashes.
- Reduced trust: Insecure hashes can erode the trust that users and customers have in a system or application. This can result in reputational damage and financial losses.
Several measures can prevent the use of insecure hashes, including:
- Use strong cryptographic hash functions: Use strong and up-to-date cryptographic hash functions that have been widely tested and validated by security experts, such as SHA-256 or SHA-3. Avoid using outdated hash functions like MD5 or SHA-1, which are known to be insecure.
- Use appropriate hash lengths: Use appropriate hash lengths to ensure that the cryptographic hashes generated are strong enough to resist attacks. Longer hash lengths are generally more secure and harder to break.
- Use salt values: Use salt values to further strengthen the security of the cryptographic hashes generated. Salt values are random data that are added to the original data before hashing, which makes it harder for attackers to use precomputed tables or dictionaries to break the hashes.
- Regularly update software and systems: Regularly update software and systems to ensure that the latest security patches are applied and known vulnerabilities related to insecure hashes are addressed.
- Regularly review and update security policies and procedures: Regularly review and update security policies and procedures to ensure that they remain up-to-date with the latest best practices and standards.
References
Taxonomies
- OWASP Top 10 - A02 Cryptographic Failures
- CWE-328: Use of Weak Hash
- CWE-916: Use of Password Hash With Insufficient Computational Effort
Explanation & Prevention
- OWASP: Using a broken or risky cryptographic algorithm article
- OWASP: Cryptographic Storage Cheat Sheet
- OWASP: Password Storage Cheat Sheet
- OWASP: Testing for Weak Encryption
