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

ClassDraftExploit Likelihood: High

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

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Extended Description

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.

Technical Details

Structure
Simple

Applicable To

Languages
VerilogVHDLNot Language-Specific
Platforms

Frequently Asked Questions

What is CWE-327: Use of a Broken or Risky Cryptographic Algorithm?+

CWE-327: Use of a Broken or Risky Cryptographic Algorithm is a Common Weakness Enumeration (CWE) entry maintained by MITRE. 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.

What are the security consequences of Use of a Broken or Risky Cryptographic Algorithm?+

If exploited, CWE-327 (Use of a Broken or Risky Cryptographic Algorithm) it can compromise Confidentiality, Integrity, Accountability and Non-Repudiation, leading to outcomes such as Read Application Data, Modify Application Data and Hide Activities.

How do you prevent or mitigate Use of a Broken or Risky Cryptographic Algorithm?+

Recommended mitigations for CWE-327 include: 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.

How is Use of a Broken or Risky Cryptographic Algorithm detected?+

CWE-327 can be detected using Automated Analysis, Dynamic Analysis with Manual Results Interpretation, Manual Static Analysis - Source Code, Automated Static Analysis - Source Code and Architecture or Design Review. Combining automated tooling with manual review typically yields the best coverage.

Which programming languages are affected by Use of a Broken or Risky Cryptographic Algorithm?+

CWE-327 commonly affects Verilog, VHDL and Not Language-Specific. Note that weaknesses are often language-agnostic patterns, so secure coding practices apply broadly.

What are real-world examples of Use of a Broken or Risky Cryptographic Algorithm?+

MITRE documents real CVEs mapped to CWE-327, including CVE-2022-30273, CVE-2022-30320, CVE-2008-3775, CVE-2007-4150 and CVE-2007-5460. You can look up the full details of each CVE, including CVSS scores and remediation guidance, on our CVE Lookup tool.

What is the difference between a CWE and a CVE?+

A CWE (Common Weakness Enumeration) like CWE-327 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.

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