CWE-665: Improper Initialization

Causes

• 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.
• The following code intends to limit certain operations to the administrator only. 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.
• 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.

Remediation

• Requirements: [object Object]
• Architecture and Design: Identify all variables and data stores that receive information from external sources, and apply input validation to make sure that they are only initialized to expected values.
• Implementation: Explicitly initialize all your variables and other data stores, either during declaration or just before the first usage.
• Implementation: Pay close attention to complex conditionals that affect initialization, since some conditions might not perform the initialization.
• Implementation: Avoid race conditions (CWE-362) during initialization routines.
• Build and Compilation: Run or compile your product with settings that generate warnings about uninitialized variables or data.

Detection

• Automated Dynamic Analysis: [object Object]
• Manual Dynamic Analysis: Identify error conditions that are not likely to occur during normal usage and trigger them. For example, run the program under low memory conditions, run with insufficient privileges or permissions, interrupt a transaction before it is completed, or disable connectivity to basic network services such as DNS. Monitor the software for any unexpected behavior. If you trigger an unhandled exception or similar error that was discovered and handled by the application's environment, it may still indicate unexpected conditions that were not handled by the application itself.
• 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.)

Related CWEs

• CWE-1188: Initialization of a Resource with an Insecure Default
• CWE-1279: Cryptographic Operations are run Before Supporting Units are Ready
• CWE-1419: Incorrect Initialization of Resource
• CWE-1434: Insecure Setting of Generative AI/ML Model Inference Parameters
• CWE-455: Non-exit on Failed Initialization
• CWE-456: Missing Initialization of a Variable
• CWE-456: Missing Initialization of a Variable
• CWE-457: Use of Uninitialized Variable
• CWE-457: Use of Uninitialized Variable
• CWE-664: Improper Control of a Resource Through its Lifetime
• CWE-770: Allocation of Resources Without Limits or Throttling
• CWE-908: Use of Uninitialized Resource

Related CVEs

Related CVE mappings appear after CVE records are cross-indexed.

ATT&CK Relevance

ATT&CK relevance is shown only when reviewed or responsibly inferred.