CWE

Common Weakness Enumeration

A community-developed list of SW & HW weaknesses that can become vulnerabilities

New to CWE? click here!
CWE Most Important Hardware Weaknesses
CWE Top 25 Most Dangerous Weaknesses
Home > CWE List > CWE-521: Weak Password Requirements (4.16)  
ID

CWE-521: Weak Password Requirements

Weakness ID: 521
Vulnerability Mapping: ALLOWED This CWE ID may be used to map to real-world vulnerabilities
Abstraction: Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.
View customized information:
For users who are interested in more notional aspects of a weakness. Example: educators, technical writers, and project/program managers. For users who are concerned with the practical application and details about the nature of a weakness and how to prevent it from happening. Example: tool developers, security researchers, pen-testers, incident response analysts. For users who are mapping an issue to CWE/CAPEC IDs, i.e., finding the most appropriate CWE for a specific issue (e.g., a CVE record). Example: tool developers, security researchers. For users who wish to see all available information for the CWE/CAPEC entry. For users who want to customize what details are displayed.
×

Edit Custom Filter


+ Description
The product does not require that users should have strong passwords, which makes it easier for attackers to compromise user accounts.
+ Extended Description
Authentication mechanisms often rely on a memorized secret (also known as a password) to provide an assertion of identity for a user of a system. It is therefore important that this password be of sufficient complexity and impractical for an adversary to guess. The specific requirements around how complex a password needs to be depends on the type of system being protected. Selecting the correct password requirements and enforcing them through implementation are critical to the overall success of the authentication mechanism.
+ Common Consequences
Section HelpThis table specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.
Scope Impact Likelihood
Access Control

Technical Impact: Gain Privileges or Assume Identity

An attacker could easily guess user passwords and gain access user accounts.
+ Potential Mitigations

Phase: Architecture and Design

A product's design should require adherance to an appropriate password policy. Specific password requirements depend strongly on contextual factors, but it is recommended to contain the following attributes:

  • Enforcement of a minimum and maximum length
  • Restrictions against password reuse
  • Restrictions against using common passwords
  • Restrictions against using contextual string in the password (e.g., user id, app name)

Depending on the threat model, the password policy may include several additional attributes.

  • Complex passwords requiring mixed character sets (alpha, numeric, special, mixed case)
    • Increasing the range of characters makes the password harder to crack and may be appropriate for systems relying on single factor authentication.
    • Unfortunately, a complex password may be difficult to memorize, encouraging a user to select a short password or to incorrectly manage the password (write it down).
    • Another disadvantage of this approach is that it often does not result in a significant increases in overal password complexity due to people's predictable usage of various symbols.
  • Large Minimum Length (encouraging passphrases instead of passwords)
    • Increasing the number of characters makes the password harder to crack and may be appropriate for systems relying on single factor authentication.
    • A disadvantage of this approach is that selecting a good passphrase is not easy and poor passwords can still be generated. Some prompting may be needed to encourage long un-predictable passwords.
  • Randomly Chosen Secrets
    • Generating a password for the user can help make sure that length and complexity requirements are met, and can result in secure passwords being used.
    • A disadvantage of this approach is that the resulting password or passpharse may be too difficult to memorize, encouraging them to be written down.
  • Password Expiration
    • Requiring a periodic password change can reduce the time window that an adversary has to crack a password, while also limiting the damage caused by password exposures at other locations.
    • Password expiration may be a good mitigating technique when long complex passwords are not desired.

See NIST 800-63B [REF-1053] for further information on password requirements.

Phase: Architecture and Design

Consider a second authentication factor beyond the password, which prevents the password from being a single point of failure. See CWE-308 for further information.

Phase: Implementation

Consider implementing a password complexity meter to inform users when a chosen password meets the required attributes.
+ Relationships
Section Help This table shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.
+ Relevant to the view "Research Concepts" (CWE-1000)
Nature Type ID Name
ChildOf Class Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource. 1391 Use of Weak Credentials
ParentOf Variant Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource. 258 Empty Password in Configuration File
Section Help This table shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.
+ Relevant to the view "Software Development" (CWE-699)
Nature Type ID Name
MemberOf Category Category - a CWE entry that contains a set of other entries that share a common characteristic. 255 Credentials Management Errors
Section Help This table shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.
+ Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (CWE-1003)
Nature Type ID Name
ChildOf Class Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource. 287 Improper Authentication
Section Help This table shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.
+ Relevant to the view "Architectural Concepts" (CWE-1008)
Nature Type ID Name
MemberOf Category Category - a CWE entry that contains a set of other entries that share a common characteristic. 1010 Authenticate Actors
+ Modes Of Introduction
Section HelpThe different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.
Phase Note
Architecture and Design COMMISSION: This weakness refers to an incorrect design related to an architectural security tactic.
Implementation Not enforcing the password policy stated in a products design can allow users to create passwords that do not provide the necessary level of protection.
+ Applicable Platforms
Section HelpThis listing shows possible areas for which the given weakness could appear. These may be for specific named Languages, Operating Systems, Architectures, Paradigms, Technologies, or a class of such platforms. The platform is listed along with how frequently the given weakness appears for that instance.

Languages

Class: Not Language-Specific (Undetermined Prevalence)

Technologies

Class: Not Technology-Specific (Undetermined Prevalence)

+ Observed Examples
Reference Description
key server application does not require strong passwords
+ Detection Methods

Automated Static Analysis

Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)

Effectiveness: High

+ Memberships
Section HelpThis MemberOf Relationships table shows additional CWE Categories and Views that reference this weakness as a member. This information is often useful in understanding where a weakness fits within the context of external information sources.
Nature Type ID Name
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 724 OWASP Top Ten 2004 Category A3 - Broken Authentication and Session Management
MemberOf ViewView - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). 884 CWE Cross-section
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 951 SFP Secondary Cluster: Insecure Authentication Policy
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1353 OWASP Top Ten 2021 Category A07:2021 - Identification and Authentication Failures
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1396 Comprehensive Categorization: Access Control
+ Vulnerability Mapping Notes

Usage: ALLOWED

(this CWE ID may be used to map to real-world vulnerabilities)

Reason: Acceptable-Use

Rationale:

This CWE entry is at the Base level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.

Comments:

Carefully read both the name and description to ensure that this mapping is an appropriate fit. Do not try to 'force' a mapping to a lower-level Base/Variant simply to comply with this preferred level of abstraction.
+ Taxonomy Mappings
Mapped Taxonomy Name Node ID Fit Mapped Node Name
OWASP Top Ten 2004 A3 CWE More Specific Broken Authentication and Session Management
+ References
[REF-44] Michael Howard, David LeBlanc and John Viega. "24 Deadly Sins of Software Security". "Sin 19: Use of Weak Password-Based Systems." Page 279. McGraw-Hill. 2010.
[REF-1053] NIST. "Digital Identity Guidelines (SP 800-63B)". Sections: 5.1.1, 10.2.1, and Appendix A. 2017-06. <https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-63b.pdf>. URL validated: 2023-04-07.
+ Content History
+ Submissions
Submission Date Submitter Organization
2006-07-19
(CWE Draft 3, 2006-07-19)
Anonymous Tool Vendor (under NDA)
+ Modifications
Modification Date Modifier Organization
2008-07-01 Eric Dalci Cigital
updated Potential_Mitigations, Time_of_Introduction
2008-08-15 Veracode
Suggested OWASP Top Ten 2004 mapping
2008-09-08 CWE Content Team MITRE
updated Description, Relationships, Taxonomy_Mappings
2009-05-27 CWE Content Team MITRE
updated Related_Attack_Patterns
2011-03-29 CWE Content Team MITRE
updated Potential_Mitigations, Relationships
2011-06-01 CWE Content Team MITRE
updated Common_Consequences
2012-05-11 CWE Content Team MITRE
updated Common_Consequences, References, Relationships
2014-07-30 CWE Content Team MITRE
updated Relationships
2017-11-08 CWE Content Team MITRE
updated Modes_of_Introduction, Relationships, Taxonomy_Mappings
2019-06-20 CWE Content Team MITRE
updated Relationships
2020-02-24 CWE Content Team MITRE
updated Applicable_Platforms, Description, Modes_of_Introduction, Potential_Mitigations, References
2020-08-20 CWE Content Team MITRE
updated Related_Attack_Patterns
2021-10-28 CWE Content Team MITRE
updated Relationships
2022-10-13 CWE Content Team MITRE
updated Observed_Examples, Potential_Mitigations, Relationships
2023-04-27 CWE Content Team MITRE
updated Detection_Factors, Relationships
2023-06-29 CWE Content Team MITRE
updated Mapping_Notes
Page Last Updated: November 19, 2024