CWE-93

Improper Neutralization of CRLF Sequences ('CRLF Injection')

Weakness Description

The product uses CRLF (carriage return line feeds) as a special element, e.g. to separate lines or records, but it does not neutralize or incorrectly neutralizes CRLF sequences from inputs.

Potential Mitigations

Implementation

Avoid using CRLF as a special sequence.

Implementation

Appropriately filter or quote CRLF sequences in user-controlled input.

Common Consequences

Integrity
Modify Application Data

Detection Methods

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.)

Effectiveness: High

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