CWE-483: Incorrect Block Delimitation
Official CWE-483 CWE context with Glexia analysis, remediation guidance, related CVEs, and ATT&CK context.
Glexia's Take
CWE-483: Incorrect Block Delimitation
Incorrect Block Delimitation represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Executive Impact
- Confidentiality,Integrity,Availability: Alter Execution Logic: This is a general logic error which will often lead to obviously-incorrect behaviors that are quickly noticed and fixed. In lightly tested or untested code, this error may be introduced it into a production environment and provide additional attack vectors by creating a control flow path leading to an unexpected state in the application. The consequences will depend on the types of behaviors that are being incorrectly executed.
Developer Pattern
CWE-483 is the kind of defect developers can usually prevent with explicit validation, safer framework defaults, and tests that exercise hostile input or unsafe state transitions.
Confidence
high confidence from CWE-483, 4.20.
Official CWE Definition
CWE-483: Incorrect Block Delimitation
The code does not explicitly delimit a block that is intended to contain 2 or more statements, creating a logic error.
In some languages, braces (or other delimiters) are optional for blocks. When the delimiter is omitted, it is possible to insert a logic error in which a statement is thought to be in a block but is not. In some cases, the logic error can have security implications.
Developer And Remediation Guidance
How teams prevent and detect this weakness
Causes
- In this example, the programmer has indented the statements to call Do_X() and Do_Y(), as if the intention is that these functions are only called when the condition is true. However, because there are no braces to signify the block, Do_Y() will always be executed, even if the condition is false. This might not be what the programmer intended. When the condition is critical for security, such as in making a security decision or detecting a critical error, this may produce a vulnerability.
- In this example, the programmer has indented the Do_Y() statement as if the intention is that the function should be associated with the preceding conditional and should only be called when the condition is true. However, because Do_X() was called on the same line as the conditional and there are no braces to signify the block, Do_Y() will always be executed, even if the condition is false. This might not be what the programmer intended. When the condition is critical for security, such as in making a security decision or detecting a critical error, this may produce a vulnerability.
Remediation
- Implementation: Always use explicit block delimitation and use static-analysis technologies to enforce this practice.
Detection
- 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.)
Mappings
Related CVEs, CWEs, and ATT&CK context
ATT&CK Relevance
ATT&CK relevance is shown only when reviewed or responsibly inferred.