Remember CRLF
Full name: Carriage Return Line Feed
Memory aid: Carriage Returns, then the Line Feeds.
CRLF is a character sequence; injection occurs when untrusted data changes protocol structure.
Study area: Threats & application security · Batch 8
Relevant study for: CompTIA Security+ SY0-701 · ISC2 CISSP 2024 outline · CompTIA CySA+ · CompTIA PenTest+
Practice with exam flashcards →Cybersecurity & Identity / Knowledge library
CRLF — Carriage Return Line Feed
Names a control-character sequence that can be abused in text-based protocol injection.
Why learn CRLF — Carriage Return Line Feed?
Names a control-character sequence that can be abused in text-based protocol injection.
Where it came from
CRLF is a character sequence; injection occurs when untrusted data changes protocol structure.
- Memory aid (a learning cue, not the expansion): Carriage Returns, then the Line Feeds.
Build your understanding
Work through these exercises in order. Try the task before opening a reference.
- Without looking, expand CRLF: Carriage Return Line Feed.
- Recall this memory aid: Carriage Returns, then the Line Feeds.
- Explain the practical use: Names a control-character sequence that can be abused in text-based protocol injection.
- Explain this distinction: CRLF is a character sequence; injection occurs when untrusted data changes protocol structure.
- Identify CRLF in a device specification, architecture diagram, or system inventory.
Documentation and sources
- IETF RFC 9112 (www.rfc-editor.org)