CWE-327: Use of a Broken or Risky Cryptographic Algorithm

Description

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 algorithm to be considered "unsafe" even if it was once thought to be strong. This can happen when new attacks are discovered, or if computing power increases so much that the cryptographic algorithm no longer provides the amount of protection that was originally thought. For a number of reasons, this weakness is even more challenging to manage with hardware deployment of cryptographic algorithms as opposed to software implementation. First, if a flaw is discovered with hardware-implemented cryptography, the flaw cannot be fixed in most cases without a recall of the product, because hardware is not easily replaceable like software. Second, because the hardware product is expected to work for years, the adversary's computing power will only increase over time.

Potential Impact

Demonstrative Examples

EVP_des_ecb();

Cipher des=Cipher.getInstance("DES...");des.initEncrypt(key2);

function encryptPassword($password){$iv_size = mcrypt_get_iv_size(MCRYPT_DES, MCRYPT_MODE_ECB);$iv = mcrypt_create_iv($iv_size, MCRYPT_RAND);$key = "This is a password encryption key";$encryptedPassword = mcrypt_encrypt(MCRYPT_DES, $key, $password, MCRYPT_MODE_ECB, $iv);return $encryptedPassword;}

The manufacturer chooses a SHA1 hardware accelerator for to implement the scheme because it already has a working SHA1 Intellectual Property (IP) that the manufacturer had created and used earlier, so this reuse of IP saves design cost.

The manufacturer could have chosen a cryptographic solution that is recommended by the wide security community (including standard-setting bodies like NIST) and is not expected to be broken (or even better, weakened) within the reasonable life expectancy of the hardware product. In this case, the architects could have used SHA-2 or SHA-3, even if it meant that such choice would cost extra.

Mitigations & Prevention

Detection Methods

• Automated Analysis Moderate — Automated methods may be useful for recognizing commonly-used libraries or features that have become obsolete.
• Manual Analysis — This weakness can be detected using tools and techniques that require manual (human) analysis, such as penetration testing, threat modeling, and interactive tools that allow the tester to record and modify an active session.
• Automated Static Analysis - Binary or Bytecode SOAR Partial — According to SOAR [REF-1479], the following detection techniques may be useful:
• Manual Static Analysis - Binary or Bytecode SOAR Partial — According to SOAR [REF-1479], the following detection techniques may be useful:
• Dynamic Analysis with Automated Results Interpretation SOAR Partial — According to SOAR [REF-1479], the following detection techniques may be useful:
• Dynamic Analysis with Manual Results Interpretation High — According to SOAR [REF-1479], the following detection techniques may be useful:

Real-World CVE Examples

Related Weaknesses

Taxonomy Mappings

• CLASP: — Using a broken or risky cryptographic algorithm
• OWASP Top Ten 2004: A8 — Insecure Storage
• CERT C Secure Coding: MSC30-C — Do not use the rand() function for generating pseudorandom numbers
• CERT C Secure Coding: MSC32-C — Properly seed pseudorandom number generators
• The CERT Oracle Secure Coding Standard for Java (2011): MSC02-J — Generate strong random numbers
• OMG ASCSM: ASCSM-CWE-327 —
• ISA/IEC 62443: Part 3-3 — Req SR 4.3
• ISA/IEC 62443: Part 4-2 — Req CR 4.3