Incorrect Block Delimitation

Opis

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.

Skutki

• 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.

Zapobieganie

• Implementation

  Always use explicit block delimitation and use static-analysis technologies to enforce this practice.

Przykłady podatności

• CVE-2014-1266 Chain: incorrect "goto" in Apple SSL product bypasses certificate validation, allowing Adversary-in-the-Middle (AITM) attack (Apple "goto fail" bug). CWE-705 (Incorrect Control Flow Scoping) -> CWE-561 (Dead Code) -> CWE-295 (Improper Certificate Validation) -> CWE-393 (Return of Wrong Status Code) -> CWE-300 (Channel Accessible by Non-Endpoint). The code's whitespace indentation did not reflect the actual control flow (CWE-1114) and did not explicitly delimit the block (CWE-483), which could have made it more difficult for human code auditors to detect the vulnerability.

Słabość nadrzędna

• CWE-670 Always-Incorrect Control Flow Implementation

Kiedy powstaje

• Implementation

Dotyczy

C, C++

Źródła

1. The CLASP Application Security Process — Secure Software, Inc., 2005