Mobile attack vector library

Prompt injection attacks: Risks, consequences, and best practices for secure apps

Written by Admin | Dec 19, 2025 12:48:23 PM

Overview

A prompt injection attack (PIA) happens when attackers hide malicious instructions inside normal-looking user input. These instructions trick the AI system into following their commands instead of its intended rules. The AI is then manipulated into executing unintended actions, such as leaking sensitive data or ignoring safeguards. Because AI models read natural language as direct instruction, these attacks exploit the trust placed in inputs. As AI becomes embedded in business-critical apps, prompt injection attacks represent a growing challenge to security, compliance, and trust

Risk factors

Prompt injection attacks can arise from:

  • AI systems processing untrusted user input without strong filtering.
  • Third-party data sources (web, APIs, files) feeding directly into AI prompts.
  • Using prompts that are long, complex, or difficult to monitor for hidden commands.
  • AI taking autonomous actions in applications without human oversight.
  • Organizations and developers relying on AI models without implementing guardrails.
  • Sharing prompts or outputs publicly, so attackers can craft malicious input.

Consequences

If a prompt injection attack is exploited, the following can happen:

  • Data leakage: Confidential or sensitive data may be exposed.
  • Policy bypass: Security rules, compliance filters, or access controls can be overridden.
  • Malicious actions: Malicious instructions may trigger harmful or unauthorized actions.
  • Damage to reputation: Trust in the app and the organization can be damaged.
  • Compliance violations: Regulatory requirements may be breached, triggering legal and penalties.

Solutions and best practices

To mitigate the risks associated with prompt injection attacks, organizations should:

  • Validate and filter inputs: Attempt to detect known attack patterns, although reply on architectural defenses (like context separation) as the primary barrier.
  • Apply context separation: Clearly distinguish system-level instructions from user-provided content.
  • Monitor AI: Behavior should be logged continuously to detect anomalies or suspicious activity.
  • Apply the Principle of Least Privilege: Restrict what AI systems are allowed to do for sensitive operations by applying least-privilege access.
  • Test AI systems: Regularly test AI systems with red-teaming against known prompt injection attack patterns to uncover vulnerabilities.
  • Strengthen resilience: Enhance defenses with multi-layered security, such as runtime protection and app attestation.
  • Team training: Build team awareness around secure prompt design and engineering, and the risks of prompt injection attacks.