CWE-328: Use of Weak Hash | Glexia
CWE-328 (Use of Weak Hash) weakness overview with consequences, detection methods, mitigations, related CVEs and MITRE ATT&CK context.
Glexia's Take · Automated analysis
CWE-328: Use of Weak Hash
Use of Weak Hash represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Executive Impact
- Access Control: Bypass Protection Mechanism
Developer Pattern
CWE-328 is the kind of defect developers can usually prevent with explicit validation, safer framework defaults, and tests that exercise hostile input or unsafe state transitions.
Automation confidence
high confidence from CWE-328, 4.20.
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Official CWE Definition
CWE-328: Use of Weak Hash
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).
Developer And Remediation Guidance
How teams prevent and detect this weakness
Causes
- In both of these examples, a user is logged in if their given password matches a stored password: This code relies exclusively on a password mechanism (CWE-309) using only one factor of authentication (CWE-308). If an attacker can steal or guess a user's password, they are given full access to their account. Note this code also uses SHA-1, which is a weak hash (CWE-328). It also does not use a salt (CWE-759).
- In 2022, the OT:ICEFALL study examined products by 10 different Operational Technology (OT) vendors. The researchers reported 56 vulnerabilities and said that the products were "insecure by design" [REF-1283]. If exploited, these vulnerabilities often allowed adversaries to change how the products operated, ranging from denial of service to changing the code that the products executed. Since these products were often used in industries such as power, electrical, water, and others, there could even be safety implications. At least one OT product used weak hashes.
- The example code below is taken from the JTAG access control mechanism of the Hack@DAC'21 buggy OpenPiton SoC [REF-1360]. Access to JTAG allows users to access sensitive information in the system. Hence, access to JTAG is controlled using cryptographic authentication of the users. In this example (see the vulnerable code source), the password checker uses HMAC-SHA256 for authentication. It takes a 512-bit secret message from the user, hashes it using HMAC, and compares its output with the expected output to determine the authenticity of the user. The vulnerable code shows an incorrect implementation of the HMAC authentication where it only uses the least significant 32 bits of the secret message for the authentication (the remaining 480 bits are hard coded as zeros). As a result, the system is susceptible to brute-force attacks where the attacker only needs to determine 32 bits of the secret message instead of 512 bits, weakening the cryptographic protocol.,To mitigate, remove the zero padding and use all 512 bits of the secret message for HMAC authentication [REF-1361].
Remediation
- Architecture and Design:
Detection
- Automated Static Analysis: Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)
Mappings
Related CVEs, CWEs, and ATT&CK context
Related CWEs
ATT&CK Relevance
ATT&CK relevance is shown only when reviewed or responsibly inferred.