The product does not initialize a critical resource.
Extended Description
Many resources require initialization before they can be properly used. If a resource is not initialized, it could contain unpredictable or expired data, or it could be initialized to defaults that are invalid. This can have security implications when the resource is expected to have certain properties or values.
Relationships
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 - 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.
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.
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.
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.
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 - a CWE entry that contains a set of other entries that share a common characteristic.
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 - 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.
The 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
This 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)
Common Consequences
This 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
Confidentiality
Technical Impact: Read Memory; Read Application Data
When reusing a resource such as memory or a program variable, the original contents of that resource may not be cleared before it is sent to an untrusted party.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
The uninitialized resource may contain values that cause program flow to change in ways that the programmer did not intend.
Likelihood Of Exploit
Medium
Demonstrative Examples
Example 1
Here, a boolean initiailized field is consulted to ensure that initialization tasks are only completed once. However, the field is mistakenly set to true during static initialization, so the initialization code is never reached.
(bad code)
Example Language: Java
private boolean initialized = true; public void someMethod() {
if (!initialized) {
// perform initialization tasks ...
initialized = true;
}
Example 2
The following code intends to limit certain operations to the administrator only.
(bad code)
Example Language: Perl
$username = GetCurrentUser(); $state = GetStateData($username); if (defined($state)) {
$uid = ExtractUserID($state);
}
# do stuff if ($uid == 0) {
DoAdminThings();
}
If the application is unable to extract the state information - say, due to a database timeout - then the $uid variable will not be explicitly set by the programmer. This will cause $uid to be regarded as equivalent to "0" in the conditional, allowing the original user to perform administrator actions. Even if the attacker cannot directly influence the state data, unexpected errors could cause incorrect privileges to be assigned to a user just by accident.
Example 3
The following code intends to concatenate a string to a variable and print the string.
This might seem innocent enough, but str was not initialized, so it contains random memory. As a result, str[0] might not contain the null terminator, so the copy might start at an offset other than 0. The consequences can vary, depending on the underlying memory.
If a null terminator is found before str[8], then some bytes of random garbage will be printed before the "hello world" string. The memory might contain sensitive information from previous uses, such as a password (which might occur as a result of CWE-14 or CWE-244). In this example, it might not be a big deal, but consider what could happen if large amounts of memory are printed out before the null terminator is found.
If a null terminator isn't found before str[8], then a buffer overflow could occur, since strcat will first look for the null terminator, then copy 12 bytes starting with that location. Alternately, a buffer over-read might occur (CWE-126) if a null terminator isn't found before the end of the memory segment is reached, leading to a segmentation fault and crash.
Example 4
This example will leave test_string in an unknown condition when i is the same value as err_val, because test_string is not initialized (CWE-456). Depending on where this code segment appears (e.g. within a function body), test_string might be random if it is stored on the heap or stack. If the variable is declared in static memory, it might be zero or NULL. Compiler optimization might contribute to the unpredictability of this address.
(bad code)
Example Language: C
char *test_string;
if (i != err_val)
{
test_string = "Hello World!";
}
printf("%s", test_string);
When the printf() is reached, test_string might be an unexpected address, so the printf might print junk strings (CWE-457).
To fix this code, there are a couple approaches to
making sure that test_string has been properly set once
it reaches the printf().
One solution would be to set test_string to an
acceptable default before the conditional:
(good code)
Example Language: C
char *test_string = "Done at the beginning";
if (i != err_val)
{
test_string = "Hello World!";
}
printf("%s", test_string);
Another solution is to ensure that each
branch of the conditional - including the default/else
branch - could ensure that test_string is set:
Chain: Bypass of access restrictions due to improper authorization (CWE-862) of a user results from an improperly initialized (CWE-909) I/O permission bitmap
Potential Mitigations
Phase: Implementation
Explicitly initialize the resource before use. If this is performed through an API function or standard procedure, follow all specified steps.
Phase: Implementation
Pay close attention to complex conditionals that affect initialization, since some branches might not perform the initialization.
Phase: Implementation
Avoid race conditions (CWE-362) during initialization routines.
Phase: Build and Compilation
Run or compile your product with settings that generate warnings about uninitialized variables or data.
Weakness Ordinalities
Ordinality
Description
Primary
(where the weakness exists independent of other weaknesses)
Resultant
(where the weakness is typically related to the presence of some other weaknesses)
Content History
Submissions
Submission Date
Submitter
Organization
2012-12-21
CWE Content Team
MITRE
New weakness based on discussion on the CWE research list in December 2012.
Description
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)
