CWE-328: Use of Weak Hash

CWE-328: Use of Weak Hash is a Common Weakness Enumeration (CWE) entry maintained by MITRE. The product uses an algorithm that produces a digest (output value) that does not meet security expectations for a hash function that allows an adversary to reasonably determine the original input (preimage attack), find another input that can produce the same hash (2nd preimage attack), or find multiple inputs that evaluate to the same hash (birthday attack). A hash function is defined as an algorithm that maps arbitrarily sized data into a fixed-sized digest (output) such that the following properties hold: The algorithm is not invertible (also called "one-way" or "not reversible") The algorithm is deterministic; the same input produces the same digest every time Building on this definition, a cryptographic hash function must also ensure that a malicious actor cannot leverage the hash function to have a reasonable chance of success at determining any of the following: the original input (preimage attack), given only the digest another input that can produce the same digest (2nd preimage attack), given the original input a set of two or more inputs that evaluate to the same digest (birthday attack), given the actor can arbitrarily choose the inputs to be hashed and can do so a reasonable amount of times What is regarded as "reasonable" varies by context and threat model, but in general, "reasonable" could cover any attack that is more efficient than brute force (i.e., on average, attempting half of all possible combinations). Note that some attacks might be more efficient than brute force but are still not regarded as achievable in the real world. Any algorithm that does not meet the above conditions will generally be considered weak for general use in hashing. In addition to algorithmic weaknesses, a hash function can be made weak by using the hash in a security context that breaks its security guarantees. For example, using a hash function without a salt for storing passwords (that are sufficiently short) could enable an adversary to create a "rainbow table" [REF-637] to recover the password under certain conditions; this attack works against such hash functions as MD5, SHA-1, and SHA-2.

If exploited, CWE-328 (Use of Weak Hash) it can compromise Access Control, leading to outcomes such as Bypass Protection Mechanism.

CWE-328 commonly affects Not Language-Specific. Note that weaknesses are often language-agnostic patterns, so secure coding practices apply broadly.

MITRE documents real CVEs mapped to CWE-328, including CVE-2022-30320, CVE-2005-4900, CVE-2020-25685, CVE-2012-6707 and CVE-2019-14855. You can look up the full details of each CVE, including CVSS scores and remediation guidance, on our CVE Lookup tool.

A CWE (Common Weakness Enumeration) like CWE-328 describes a category of software weakness — the underlying flaw type. A CVE (Common Vulnerabilities and Exposures) identifies a specific, real-world vulnerability in a particular product. In short, a CWE is the kind of mistake, and a CVE is an instance of that mistake being found in software.