What is a prompt injection attack? Meaning and what causes it to happen

What is a prompt injection attack?

A prompt injection attack is a type of security vulnerability that allows someone to manipulate an AI system, usually a large language model, through carefully crafted text inputs. These attacks can cause AI to ignore its original instructions, perform unintended actions, or even leak sensitive information.

As AI tools become more widely adopted in business settings, understanding how prompt injection works is critical for protecting systems and data.

Where did prompt injection attacks come from?

Prompt injection attacks emerged as researchers and developers began probing the limits of large language models. The idea is conceptually similar to SQL injection—a well-known method of inserting malicious code into database queries.

The term “prompt injection” was first introduced by security researcher Riley Goodside. He showed how simple text inputs could override a language model’s original instructions and modify its behavior. His early work drew attention across the AI security community, highlighting how easily these models could be misdirected.

What began as exploratory research has now evolved into a serious security concern. As AI systems become part of core business operations, prompt injection has shifted from a theoretical risk to a practical threat.

How does prompt injection work?

Prompt injection works by exploiting how language models interpret and prioritize instructions. Attackers craft text inputs designed to override or subvert the model’s intended behavior.

There are two main forms of prompt injection:

• Direct prompt injection: Tells the AI explicitly to ignore prior instructions
• Indirect prompt injection: Embeds malicious or misleading content in a way that manipulates the model’s output through context or framing

What makes prompt injection especially dangerous is its simplicity. No advanced hacking tools are required, just carefully worded text.

Imagine a company uses an AI-powered customer service chatbot trained to follow strict privacy rules. An attacker can send a message to the system to ignore previous instructions about data privacy and leak customer information. If the model isn’t properly secured, it might comply, revealing private data it was never supposed to disclose. And all it took was a few sentences.

Why is navigating prompt injections important to understand?

Prompt injection exposes a new class of vulnerabilities that traditional security tools aren’t designed to catch. As businesses use AI to automate customer interactions, generate content, and process sensitive data, these risks can become entry points for data leaks or misuse.

By understanding how prompt injection works, security teams can:

• Build guardrails into AI applications
• Monitor for unexpected or suspicious inputs
• Develop response protocols for AI-specific threats

Proactively addressing these vulnerabilities helps organizations deploy AI responsibly and builds trust with users, partners, and regulators.

From a practical standpoint, mitigation strategies might include:

• Content review steps before AI-generated output is published
• Input filtering or sanitization in customer-facing chatbots
• System-level monitoring for prompt injection patterns and anomalies

TL;DR

Prompt injection attacks trick AI systems into ignoring their original instructions or revealing restricted information, often using nothing more than cleverly worded text. As more businesses rely on AI, understanding prompt injection helps teams close critical security gaps and deploy models more confidently.

Whether you're launching your first chatbot or building out a complex AI workflow, knowing how these systems can be manipulated is the first step to protecting them.