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.

Primary

Architecture and Design
COMMISSION: This weakness refers to an incorrect design related to an architectural security tactic.

Implementation
With hardware, the Architecture or Design Phase might start with compliant cryptography, but it is replaced with a non-compliant crypto during the later Implementation phase due to implementation constraints (e.g., not enough entropy to make it function properly, or not enough silicon real estate available to implement). Or, in rare cases (especially for long projects that span over years), the Architecture specifications might start with cryptography that was originally compliant at the time the Architectural specs were written, but over the time it became non-compliant due to progress made in attacking the crypto.

High

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.

Automated Analysis
Automated methods may be useful for recognizing commonly-used libraries or features that have become obsolete.
Moderate
False negatives may occur if the tool is not aware of the cryptographic libraries in use, or if custom cryptography is being used.

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.
These may be more effective than strictly automated techniques. This is especially the case with weaknesses that are related to design and business rules.

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.

SOAR Partial

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

SOAR Partial

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

SOAR Partial

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

High

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

High

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

High

Automated Static Analysis

According to SOAR [REF-1479], the following detection techniques may be useful:

Cost effective for partial coverage:

Configuration Checker

SOAR Partial

Architecture or Design Review

According to SOAR [REF-1479], the following detection techniques may be useful:

Highly cost effective:

Formal Methods / Correct-By-Construction

Cost effective for partial coverage:

Inspection (IEEE 1028 standard) (can apply to requirements, design, source code, etc.)

High

Architecture and Design
Libraries or Frameworks

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.
Defense in Depth

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
Libraries or Frameworks

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.

These code examples use the Data Encryption Standard (DES).

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;}

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.

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.

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.

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.

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.

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 protect integrity
https://www.cve.org/CVERecord?id=CVE-2022-30273

CVE-2022-30320
Programmable Logic Controller (PLC) uses a protocol with a cryptographically insecure hashing algorithm for passwords.
https://www.cve.org/CVERecord?id=CVE-2022-30320

CVE-2008-3775
Product uses "ROT-25" to obfuscate the password in the registry.
https://www.cve.org/CVERecord?id=CVE-2008-3775

CVE-2007-4150
product only uses "XOR" to obfuscate sensitive data
https://www.cve.org/CVERecord?id=CVE-2007-4150

CVE-2007-5460
product only uses "XOR" and a fixed key to obfuscate sensitive data
https://www.cve.org/CVERecord?id=CVE-2007-5460

CVE-2005-4860
Product substitutes characters with other characters in a fixed way, and also leaves certain input characters unchanged.
https://www.cve.org/CVERecord?id=CVE-2005-4860

CVE-2002-2058
Attackers can infer private IP addresses by dividing each octet by the MD5 hash of '20'.
https://www.cve.org/CVERecord?id=CVE-2002-2058

CVE-2008-3188
Product uses DES when MD5 has been specified in the configuration, resulting in weaker-than-expected password hashes.
https://www.cve.org/CVERecord?id=CVE-2008-3188

CVE-2005-2946
Default configuration of product uses MD5 instead of stronger algorithms that are available, simplifying forgery of certificates.
https://www.cve.org/CVERecord?id=CVE-2005-2946

CVE-2007-6013
Product uses the hash of a hash for authentication, allowing attackers to gain privileges if they can obtain the original hash.
https://www.cve.org/CVERecord?id=CVE-2007-6013

Using a broken or risky cryptographic algorithm

A8
Insecure Storage
CWE More Specific

MSC30-C
Do not use the rand() function for generating pseudorandom numbers
CWE More Abstract

MSC32-C
Properly seed pseudorandom number generators
CWE More Abstract

MSC02-J
Generate strong random numbers

ASCSM-CWE-327

Part 3-3
Req SR 4.3

Part 4-2
Req CR 4.3

Allowed-with-Review
This CWE entry is a Class and might have Base-level children that would be more appropriate
Examine children of this entry to see if there is a better fit

Since CWE 4.4, various cryptography-related entries, including CWE-327 and CWE-1240, have been slated for extensive research, analysis, and community consultation to define consistent terminology, improve relationships, and reduce overlap or duplication. As of CWE 4.6, this work is still ongoing.

CLASP
2006-07-19
Draft 3
2006-07-19

Veracode
2008-08-15
Suggested OWASP Top Ten 2004 mapping

CWE Content Team
MITRE
2008-09-08
updated Background_Details, Common_Consequences, Description, Relationships, Taxonomy_Mappings

CWE Content Team
MITRE
2009-01-12
updated Demonstrative_Examples, Description, Observed_Examples, Potential_Mitigations, References, Relationships

CWE Content Team
MITRE
2009-03-10
updated Potential_Mitigations

CWE Content Team
MITRE
2009-07-27
updated Maintenance_Notes, Relationships

CWE Content Team
MITRE
2009-10-29
updated Relationships

CWE Content Team
MITRE
2009-12-28
updated References

CWE Content Team
MITRE
2010-02-16
updated Detection_Factors, References, Relationships

CWE Content Team
MITRE
2010-04-05
updated Applicable_Platforms, Potential_Mitigations, Related_Attack_Patterns

CWE Content Team
MITRE
2010-06-21
updated Common_Consequences, Detection_Factors, Potential_Mitigations, References, Relationships

CWE Content Team
MITRE
2010-09-27
updated Potential_Mitigations, Relationships

CWE Content Team
MITRE
2011-03-29
updated Demonstrative_Examples, Description

CWE Content Team
MITRE
2011-06-01
updated Relationships, Taxonomy_Mappings

CWE Content Team
MITRE
2011-06-27
updated Relationships

CWE Content Team
MITRE
2011-09-13
updated Potential_Mitigations, Relationships, Taxonomy_Mappings

CWE Content Team
MITRE
2012-05-11
updated References, Related_Attack_Patterns, Relationships, Taxonomy_Mappings

CWE Content Team
MITRE
2012-10-30
updated Potential_Mitigations

CWE Content Team
MITRE
2013-02-21
updated Relationships

CWE Content Team
MITRE
2014-02-18
updated Related_Attack_Patterns

CWE Content Team
MITRE
2014-06-23
updated Relationships

CWE Content Team
MITRE
2014-07-30
updated Demonstrative_Examples, Detection_Factors, Relationships

CWE Content Team
MITRE
2015-12-07
updated Relationships

CWE Content Team
MITRE
2017-01-19
updated Related_Attack_Patterns

CWE Content Team
MITRE
2017-11-08
updated Demonstrative_Examples, Likelihood_of_Exploit, Modes_of_Introduction, References, Relationships, Taxonomy_Mappings

CWE Content Team
MITRE
2018-03-27
updated References, Relationships

CWE Content Team
MITRE
2019-01-03
updated References, Relationships, Taxonomy_Mappings

CWE Content Team
MITRE
2019-06-20
updated Related_Attack_Patterns, Relationships, Type

CWE Content Team
MITRE
2020-02-24
updated Applicable_Platforms, Detection_Factors, Maintenance_Notes, Relationships

CWE Content Team
MITRE
2021-03-15
updated References

CWE Content Team
MITRE
2021-10-28
updated Maintenance_Notes, Potential_Mitigations, Relationships

CWE Content Team
MITRE
2022-04-28
updated Relationships

CWE Content Team
MITRE
2022-10-13
updated Demonstrative_Examples, Observed_Examples, References

CWE Content Team
MITRE
2023-01-31
updated Applicable_Platforms, Background_Details, Demonstrative_Examples, Description, Maintenance_Notes, Modes_of_Introduction, Observed_Examples, Potential_Mitigations, References, Taxonomy_Mappings, Time_of_Introduction

CWE Content Team
MITRE
2023-04-27
updated References, Relationships

CWE Content Team
MITRE
2023-06-29
updated Mapping_Notes, Relationships

CWE Content Team
MITRE
2025-09-09
4.18
2025-09-09
updated Detection_Factors, Potential_Mitigations, References

CWE Content Team
MITRE
2025-12-11
4.19
2025-12-11
updated Maintenance_Notes, Relationships, Weakness_Ordinalities

Parbati K. Manna
Intel Corporation
2019-12-10
Provide a hardware-specific submission whose contents were integrated into this entry, affecting extended description, applicable platforms, demonstrative examples, and mitigations

Using a Broken or Risky Cryptographic Algorithm