Improper Neutralization of CRLF Sequences ('CRLF Injection')

The software 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.


Demonstrations

The following examples help to illustrate the nature of this weakness and describe methods or techniques which can be used to mitigate the risk.

Note that the examples here are by no means exhaustive and any given weakness may have many subtle varieties, each of which may require different detection methods or runtime controls.

Example One

If user input data that eventually makes it to a log message isn't checked for CRLF characters, it may be possible for an attacker to forge entries in a log file.

logger.info("User's street address: " + request.getParameter("streetAddress"));

See Also

Validate Inputs

Weaknesses in this category are related to the design and architecture of a system's input validation components. Frequently these deal with sanitizing, neutralizing a...

SFP Secondary Cluster: Tainted Input to Command

This category identifies Software Fault Patterns (SFPs) within the Tainted Input to Command cluster (SFP24).

Data Neutralization Issues

Weaknesses in this category are related to the creation or neutralization of data using an incorrect format.

Comprehensive CWE Dictionary

This view (slice) covers all the elements in CWE.

Weaknesses Introduced During Implementation

This view (slice) lists weaknesses that can be introduced during implementation.

Weaknesses Introduced During Design

This view (slice) lists weaknesses that can be introduced during design.


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