CWE WEAKNESSES  /  CWE-327

CWE-327

Use of a Broken or Risky Cryptographic Algorithm

What it is

The product uses a broken or risky cryptographic algorithm or protocol.

Cryptographic algorithms are the methods by which data is scrambled to prevent observation or influence by unauthorized actors. Insecure cryptography can be exploited to expose sensitive information, modify data in unexpected ways, spoof identities of other users or devices, or other impacts.It is very difficult to produce a secure algorithm, and even high-profile algorithms by accomplished cryptographic experts have been broken. Well-known techniques exist to break or weaken various kinds of cryptography. Accordingly, there are a small number of well-understood and heavily studied algorithms that should be used by most products. Using a non-standard or known-insecure algorithm is dangerous because a determined adversary may be able to break the algorithm and compromise whatever data has been protected.Since the state of cryptography advances so rapidly, it is common for an algorit

Impact

Mitigations

• [Architecture and Design]When there is a need to store or transmit sensitive data, use strong, up-to-date cryptographic algorithms to encrypt that data. Select a well-vetted algorithm that is currently considered to be strong by experts in the field, and use well-tested implementations. As with all cryptographic mechanisms, the source code should be available for analysis.For example, US government systems require FI
• [Architecture and Design] Ensure that the design allows one cryptographic algorithm to be replaced with another in the next generation or version. Where possible, use wrappers to make the interfaces uniform. This will make it easier to upgrade to stronger algorithms. With hardware, design the product at the Intellectual Property (IP) level so that one cryptographic algorithm can be replaced with another in the next generat
• [Architecture and Design] Carefully manage and protect cryptographic keys (see CWE-320). If the keys can be guessed or stolen, then the strength of the cryptography itself is irrelevant.
• [Architecture and Design]Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid [REF-1482].Industry-standard implementations will save development time and may be more likely to avoid errors that can occur during implementation of cryptographic algorithms. Consider the ESAPI Encryption feature.
• [Implementation, Architecture and Design] When using industry-approved techniques, use them correctly. Don't cut corners by skipping resource-intensive steps (CWE-325). These steps are often essential for preventing common attacks.

Real-world CVE examples

• CVE-2022-30273 — SCADA-based protocol supports a legacy encryption mode that uses Tiny Encryption Algorithm (TEA) in ECB mode, which leaks patterns in messages and cannot protec
• CVE-2022-30320 — Programmable Logic Controller (PLC) uses a protocol with a cryptographically insecure hashing algorithm for passwords.
• CVE-2008-3775 — Product uses "ROT-25" to obfuscate the password in the registry.
• CVE-2007-4150 — product only uses "XOR" to obfuscate sensitive data
• CVE-2007-5460 — product only uses "XOR" and a fixed key to obfuscate sensitive data
• CVE-2005-4860 — Product substitutes characters with other characters in a fixed way, and also leaves certain input characters unchanged.
• CVE-2002-2058 — Attackers can infer private IP addresses by dividing each octet by the MD5 hash of '20'.
• CVE-2008-3188 — Product uses DES when MD5 has been specified in the configuration, resulting in weaker-than-expected password hashes.
• CVE-2005-2946 — Default configuration of product uses MD5 instead of stronger algorithms that are available, simplifying forgery of certificates.
• CVE-2007-6013 — Product uses the hash of a hash for authentication, allowing attackers to gain privileges if they can obtain the original hash.

Related weaknesses

Source: MITRE CWE. View on cwe.mitre.org →