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Common Weakness Enumeration

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Home > CWE List > CWE-453: Insecure Default Variable Initialization (4.16)  
ID

CWE-453: Insecure Default Variable Initialization

Weakness ID: 453
Vulnerability Mapping: ALLOWED This CWE ID may be used to map to real-world vulnerabilities
Abstraction: 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.
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+ Description
The product, by default, initializes an internal variable with an insecure or less secure value than is possible.
+ 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
Integrity

Technical Impact: Modify Application Data

An attacker could gain access to and modify sensitive data or system information.
+ Potential Mitigations

Phase: System Configuration

Disable or change default settings when they can be used to abuse the system. Since those default settings are shipped with the product they are likely to be known by a potential attacker who is familiar with the product. For instance, default credentials should be changed or the associated accounts should be disabled.
+ 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 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. 1188 Initialization of a Resource with an Insecure Default
+ 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
Implementation
+ 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

PHP (Sometimes Prevalent)

Class: Not Language-Specific (Undetermined Prevalence)

+ Demonstrative Examples

Example 1

This code attempts to login a user using credentials from a POST request:

(bad code)
Example Language: PHP 

// $user and $pass automatically set from POST request
if (login_user($user,$pass)) {
$authorized = true;
}
...

if ($authorized) {
generatePage();
}

Because the $authorized variable is never initialized, PHP will automatically set $authorized to any value included in the POST request if register_globals is enabled. An attacker can send a POST request with an unexpected third value 'authorized' set to 'true' and gain authorized status without supplying valid credentials.

Here is a fixed version:

(good code)
Example Language: PHP 
$user = $_POST['user'];
$pass = $_POST['pass'];
$authorized = false;
if (login_user($user,$pass)) {
$authorized = true;
}
...

This code avoids the issue by initializing the $authorized variable to false and explicitly retrieving the login credentials from the $_POST variable. Regardless, register_globals should never be enabled and is disabled by default in current versions of PHP.


+ Observed Examples
Reference Description
insecure default variable initialization in BIOS firmware for a hardware board allows DoS
+ 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 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. 966 SFP Secondary Cluster: Other Exposures
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1416 Comprehensive Categorization: Resource Lifecycle Management
+ 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 Variant 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.
+ Notes

Maintenance

This overlaps other categories, probably should be split into separate items.
+ Taxonomy Mappings
Mapped Taxonomy Name Node ID Fit Mapped Node Name
PLOVER Insecure default variable initialization
+ Content History
+ Submissions
Submission Date Submitter Organization
2006-07-19
(CWE Draft 3, 2006-07-19)
PLOVER
+ Modifications
Modification Date Modifier Organization
2008-07-01 Eric Dalci Cigital
updated Potential_Mitigations, Time_of_Introduction
2008-09-08 CWE Content Team MITRE
updated Applicable_Platforms, Relationships, Other_Notes, Taxonomy_Mappings
2010-06-21 CWE Content Team MITRE
updated Maintenance_Notes, Other_Notes
2011-06-01 CWE Content Team MITRE
updated Common_Consequences
2012-05-11 CWE Content Team MITRE
updated Common_Consequences, Demonstrative_Examples, Relationships
2012-10-30 CWE Content Team MITRE
updated Potential_Mitigations
2014-07-30 CWE Content Team MITRE
updated Relationships
2017-11-08 CWE Content Team MITRE
updated Applicable_Platforms
2019-06-20 CWE Content Team MITRE
updated Relationships, Type
2020-02-24 CWE Content Team MITRE
updated Relationships, Time_of_Introduction
2023-01-31 CWE Content Team MITRE
updated Description
2023-04-27 CWE Content Team MITRE
updated Relationships, Time_of_Introduction
2023-06-29 CWE Content Team MITRE
updated Mapping_Notes
2023-10-26 CWE Content Team MITRE
updated Demonstrative_Examples, Observed_Examples
Page Last Updated: November 19, 2024