CWE-327: Use of a Broken or Risky Cryptographic Algorithm | Glexia
CWE-327 (Use of a Broken or Risky Cryptographic Algorithm) weakness overview with consequences, detection methods, mitigations, related CVEs and MITRE ATT&CK…
Glexia's Take · Automated analysis
CWE-327: Use of a Broken or Risky Cryptographic Algorithm
Use of a Broken or Risky Cryptographic Algorithm represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Executive Impact
- Confidentiality: Read Application Data: The confidentiality of sensitive data may be compromised by the use of a broken or risky cryptographic algorithm.
- Integrity: Modify Application Data: The integrity of sensitive data may be compromised by the use of a broken or risky cryptographic algorithm.
- Accountability Non-Repudiation: Hide Activities: If the cryptographic algorithm is used to ensure the identity of the source of the data (such as digital signatures), then a broken algorithm will compromise this scheme and the source of the data cannot be proven.
Developer Pattern
CWE-327 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-327, 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-327: Use of a Broken or Risky Cryptographic Algorithm
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.
Developer And Remediation Guidance
How teams prevent and detect this weakness
Causes
- These code examples use the Data Encryption Standard (DES). Once considered a strong algorithm, DES now regarded as insufficient for many applications. It has been replaced by Advanced Encryption Standard (AES).
- Suppose a chip manufacturer decides to implement a hashing scheme for verifying integrity property of certain bitstream, and it chooses to implement a SHA1 hardware accelerator for to implement the scheme. However, SHA1 was theoretically broken in 2005 and practically broken in 2017 at a cost of $110K. This means an attacker with access to cloud-rented computing power will now be able to provide a malicious bitstream with the same hash value, thereby defeating the purpose for which the hash was used. This issue could have been avoided with better design.
- 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. Multiple OT products used weak cryptography.
Remediation
- 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 FIPS 140-2 certification [REF-1192]. Do not develop custom or private cryptographic algorithms. They will likely be exposed to attacks that are well-understood by cryptographers. Reverse engineering techniques are mature. If the algorithm can be compromised if attackers find out how it works, then it is especially weak. Periodically ensure that the cryptography has not become obsolete. Some older algorithms, once thought to require a billion years of computing time, can now be broken in days or hours. This includes MD4, MD5, SHA1, DES, and other algorithms that were once regarded as strong. [REF-267]
- 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 generation of the hardware product.
- 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.
Detection
- Automated Analysis: 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: According to SOAR [REF-1479], the following detection techniques may be useful: Cost effective for partial coverage: Bytecode Weakness Analysis - including disassembler + source code weakness analysis Binary Weakness Analysis - including disassembler + source code weakness analysis Binary / Bytecode simple extractor - strings, ELF readers, etc.
- Manual Static Analysis - Binary or Bytecode: According to SOAR [REF-1479], the following detection techniques may be useful: Cost effective for partial coverage: Binary / Bytecode disassembler - then use manual analysis for vulnerabilities & anomalies
- Dynamic Analysis with Automated Results Interpretation: According to SOAR [REF-1479], the following detection techniques may be useful: Cost effective for partial coverage: Web Application Scanner Web Services Scanner Database Scanners
- Dynamic Analysis with Manual Results Interpretation: According to SOAR [REF-1479], the following detection techniques may be useful: Highly cost effective: Man-in-the-middle attack tool Cost effective for partial coverage: Framework-based Fuzzer Automated Monitored Execution Monitored Virtual Environment - run potentially malicious code in sandbox / wrapper / virtual machine, see if it does anything suspicious
- Manual Static Analysis - Source Code: According to SOAR [REF-1479], the following detection techniques may be useful: Highly cost effective: Manual Source Code Review (not inspections) Cost effective for partial coverage: Focused Manual Spotcheck - Focused manual analysis of source
- Automated Static Analysis - Source Code: According to SOAR [REF-1479], the following detection techniques may be useful: Highly cost effective: Source code Weakness Analyzer Context-configured Source Code Weakness Analyzer
Mappings
Related CVEs, CWEs, and ATT&CK context
Related CWEs
- CWE-1240: Use of a Cryptographic Primitive with a Risky Implementation
- CWE-208: Observable Timing Discrepancy
- CWE-301: Reflection Attack in an Authentication Protocol
- CWE-311: Missing Encryption of Sensitive Data
- CWE-693: Protection Mechanism Failure
- CWE-328: Use of Weak Hash
- CWE-780: Use of RSA Algorithm without OAEP
- CWE-916: Use of Password Hash With Insufficient Computational Effort
ATT&CK Relevance
ATT&CK relevance is shown only when reviewed or responsibly inferred.