LLM Security: Top 10 Risks, Impact, and Defensive Measures

What Is LLM Security?

LLM security focuses on safeguarding large language models against various threats that can compromise their functionality, integrity, and the data they process. This involves implementing measures to protect the model itself, the data it uses, and the infrastructure supporting it. The goal is to ensure that these models operate as intended without exposing sensitive information or being manipulated for malicious purposes.

In practice, LLM security encompasses a range of strategies including input sanitization, data encryption, anomaly detection, and access controls. These measures help prevent unauthorized access, data breaches, and other risks associated with deploying large language models in real-world applications. This is part of an extensive series of guides about machine learning.

Importance of LLM Security

LLM security is crucial to prevent unauthorized access and misuse of sensitive data. As these models handle vast amounts of information, a breach can lead to significant privacy violations and intellectual property theft. Ensuring data protection through encryption, access controls, and regular audits helps mitigate these risks, safeguarding the integrity and confidentiality of the information processed by LLMs.

Additionally, robust LLM security is essential for maintaining trust and reliability in AI applications. Models susceptible to manipulation can generate biased or harmful content, potentially damaging an organization’s reputation and leading to legal repercussions. By implementing comprehensive security measures, organizations developing or using LLMs can ensure they produce accurate and trustworthy outputs, fostering user confidence and upholding ethical standards in AI deployment.

Related content: Read our guide to AI privacy (coming soon)

Core Components of LLM Security

The three primary components of LLM security are securing the data, models, infrastructure, and ensuring compliance with ethical considerations.

Data Security

Data security in LLMs involves safeguarding the information these models are trained on, as well as the data they process while serving user queries. This includes measures like:

Data encryption, which ensures that data remains confidential and inaccessible to unauthorized users.
Access controls, which restrict who can interact with the data and the model, preventing unauthorized modifications or access.
Regular audits, which can help identify vulnerabilities and ensure compliance with data protection standards.

Another critical aspect of data security is mitigating risks associated with training datasets. LLMs often use vast amounts of publicly available data, which can introduce biases or incorporate sensitive information inadvertently. Techniques such as differential privacy and secure multiparty computation can be used to protect individual data points within these datasets, while maintaining overall utility for training purposes.

Model Security

Model security focuses on protecting the integrity and functionality of large language models from tampering and unauthorized modifications. This involves implementing robust measures to safeguard the model’s architecture and parameters, ensuring that only authorized changes are made. Techniques such as access controls, validation processes, and checksums are crucial for maintaining the trustworthiness of model outputs and preventing potential manipulation.

Another critical aspect of model security is defending against adversarial attacks that aim to exploit vulnerabilities in the model. These attacks can include attempts to induce biased or harmful outputs by feeding the model malicious inputs. Regular audits and anomaly detection systems are essential for identifying such threats early.

Infrastructure Security

Infrastructure security is vital for the stable operation of large language models (LLMs). This involves protecting the hardware, servers, and network connections that host these models. Implementing robust security measures like firewalls, intrusion detection systems, and encryption protocols helps guard against unauthorized access and potential threats.

Another key aspect of infrastructure security is maintaining a secure environment for data processing and storage. Regular audits and updates to the system’s security protocols are essential to address emerging vulnerabilities. It is important to ensure the physical security of data centers, implement access controls, and monitor network traffic for LLM infrastructure.

Ethical Considerations

Ethical considerations in LLM security involve preventing the generation of harmful content, misinformation, and biased outputs. This requires rigorous oversight during model training and deployment phases to ensure that the data used is diverse and representative.

Techniques like Reinforcement Learning from Human Feedback (RLHF) can be employed to align model outputs with human values, reducing the risk of generating content that could perpetuate stereotypes or incite hate speech.

Transparency and accountability are vital in managing ethical risks. Organizations must document their data sources and model training processes to facilitate audits and ensure compliance with current and future regulatory standards. Implementing robust monitoring systems helps detect and rectify unintended behaviors as quickly as possible.

OWASP Top 10 LLM Security Risks

The Open Web Application Security Project (OWASP), known for its top 10 list of application security risks, recently published a new list of security risks specifically relevant to LLM applications. Let’s review the OWASP top 10 security risks.

Prompt Injection

Prompt injection occurs when an attacker manipulates a large language model (LLM) through crafted inputs, causing it to execute unintended actions. This can be achieved directly by “jailbreaking” the system prompt or indirectly through manipulated external inputs:

In direct prompt injections, attackers overwrite or reveal the system prompt, potentially exploiting backend systems by interacting with insecure functions and data stores.
Indirect prompt injections happen when an LLM processes input from external sources controlled by an attacker, embedding malicious instructions that hijack the conversation context and lead to unpredictable or harmful outputs.

Impact: The consequences of a successful prompt injection attack can range from data exfiltration and unauthorized actions to social engineering exploits. For example, a malicious user might craft a direct prompt injection that instructs the LLM to return sensitive information or perform unauthorized operations. Indirect attacks could involve embedding rogue instructions in web content or documents processed by the LLM, leading to actions like unauthorized purchases or leaking sensitive data.

Mitigation: This risk can be mitigated by measures like privilege control on LLM access, segregating external content from user prompts, and maintaining human oversight during critical operations.

Insecure Output Handling

Insecure output handling refers to the inadequate validation, sanitization, and management of outputs generated by large language models (LLMs) before they are passed downstream to other systems. The risk arises because LLM-generated content is often controlled by prompts. When the application does not properly handle LLM outputs, it exposes itself to potential exploits that could compromise both frontend and backend systems.

Impact: This vulnerability can lead to severe security issues such as cross-site scripting (XSS), cross-site request forgery (CSRF), server-side request forgery (SSRF), privilege escalation, and remote code execution.

Mitigation: To mitigate these risks, treat the model as a user within a zero-trust framework, applying strict input validation on responses from the model. Following OWASP Application Security Verification Standard (ASVS) guidelines ensures effective input validation and sanitization. Encoding model outputs before sending them back to users can prevent undesired code execution.

Training Data Poisoning

Training data poisoning involves tampering with the data used during a model’s pre-training, fine-tuning, or embedding stages to introduce vulnerabilities. Such poisoned data not only impacts the accuracy of outputs but also poses risks like downstream software exploitation and reputational damage for organizations using these models.

Impact: This manipulation can lead to compromised model security, performance degradation, and biased outputs. Attackers might inject falsified or malicious information into the training datasets, which can then be reflected in the model’s responses.

Mitigation: Preventing training data poisoning requires rigorous verification of data sources and implementing measures like sandboxing to control data ingestion. Ensuring the legitimacy of training datasets through techniques such as ML-BOM (Machine Learning Bill of Materials) can help maintain model integrity. Additionally, using adversarial robustness strategies and continuous monitoring for anomalies can detect and mitigate poisoning attempts early on.

Model Denial of Service

Model Denial of Service (DoS) attacks on large language models (LLMs) occur when an attacker exploits the model to consume excessive computational resources. Attackers can achieve this by sending a high volume of complex or resource-intensive queries, overwhelming the system’s capacity.

Techniques such as recursive context expansion, where inputs are crafted to repeatedly trigger the model’s context window expansion, and variable-length input floods, which strain the model by exploiting inefficiencies in processing different input lengths, are common methods used in these attacks.

Impact: This attack can result in degraded service quality or complete unresponsiveness of LLM-based systems.

Mitigation: Implementing strict input validation and sanitization helps ensure that user inputs adhere to predefined limits and exclude malicious content. Limiting resource use per request and enforcing API rate limits can prevent individual users from overwhelming the system with excessive requests. Continuous monitoring of resource utilization is crucial for detecting abnormal spikes indicative of a DoS attack.

Supply Chain Vulnerabilities

Supply chain vulnerabilities in LLMs can compromise the integrity of training data, models, and deployment platforms. These vulnerabilities often arise from third-party components such as pre-trained models and datasets that may be tampered with or poisoned. Using outdated or deprecated software further exacerbates these risks.

Common examples include using compromised Python libraries, poisoned crowd-sourced data, or using vulnerable pre-trained models for fine-tuning.

Impact: Attackers can exploit these weak points to introduce biased outcomes, security breaches, or even cause complete system failures. Attack scenarios range from exploiting package registries like PyPi to distribute malicious software, to poisoning datasets that subtly favor certain entities.

Mitigation: Preventative measures involve vetting suppliers thoroughly, maintaining an up-to-date inventory of components via Software Bill of Materials (SBOM), and applying rigorous security checks on plugins and external models. Regular monitoring and anomaly detection are essential to identify and mitigate these threats promptly.

Sensitive Information Disclosure

Sensitive information disclosure in LLMs occurs when these models inadvertently reveal confidential data, proprietary algorithms, or other critical details through their outputs.

Impact: This risk can lead to unauthorized access to sensitive information, privacy violations, and compliance risk.

Mitigation: To mitigate this risk, it’s crucial for LLM applications to implement robust data sanitization techniques that prevent user data from entering the training model. Additionally, having clear Terms of Use policies can inform users about how their data is processed and provide options to opt-out of data inclusion in training.

Mitigating sensitive information disclosure also involves establishing a two-way trust boundary between the consumer and the LLM application. This means neither the input from clients nor the output from the LLM can be inherently trusted without adequate validation and filtering mechanisms in place.

Insecure Plugin Design

Insecure plugin design refers to vulnerabilities arising from the way plugins interact with large language models (LLMs). These plugins often execute automatically without stringent application controls, making them susceptible to malicious inputs.

Impact: A significant issue is the lack of input validation and type checking, allowing attackers to craft harmful requests that can lead to remote code execution or data exfiltration. Additionally, inadequate access controls between plugins can enable unauthorized actions, increasing the risk of privilege escalation and other security breaches.

Mitigation: To mitigate these risks, developers must enforce strict parameter validation and implement layered security checks on inputs. Utilizing standards such as OWASP’s Application Security Verification Standard (ASVS) ensures effective input sanitization. Thorough testing using Static Application Security Testing (SAST), Dynamic Application Security Testing (DAST), and Interactive Application Security Testing (IAST) are important for identifying this vulnerability.

Excessive Agency

Excessive Agency in large language models (LLMs) occurs when an LLM-based system is granted too much autonomy or functionality, leading to potential misuse. This vulnerability allows the model to perform unintended actions due to ambiguous outputs or malicious inputs.

The root causes of this risk include excessive functionality, permissions, and autonomy within LLM plugins or tools. For example, a plugin might offer more capabilities than necessary for its intended operation, such as allowing not just reading but also modifying and deleting documents.

Impact: Excessive agency can be a significant risk, affecting the confidentiality, integrity, and availability of systems interacting with the LLM. As LLM systems become more powerful, the magnitude of the risk and possible consequences is expected to grow.

Mitigate: To mitigate this risk, developers should limit LLM functionalities and permissions to the minimum required for specific tasks. Additionally, implementing human-in-the-loop controls where high-impact actions require human approval can prevent unintended actions. Regular monitoring and logging of plugin activities are also essential for identifying and responding to potential threats.

Overreliance

Overreliance on large language models (LLMs) occurs when users or systems trust the outputs of these models without proper oversight. The risk is greater in scenarios where LLM-generated content is public-facing or used on an ongoing basis, for example in applications like writing news articles or generating software code.

Impact: This can lead to significant issues as LLMs may produce erroneous, inappropriate, or unsafe information while presenting it authoritatively. Such “hallucinations” can spread misinformation, create legal problems, and damage reputations.

Mitigation: To mitigate overreliance risks, it’s important to regularly monitor and review LLM outputs, for example through self-consistency techniques or voting mechanisms, and filter out inaccuracies. Cross-checking model outputs with trusted external sources adds a layer of validation. Enhancing models with fine-tuning or embeddings improves output quality and reduces errors. In addition, organizations must clearly communicate risks to users.

Model Theft

Model theft refers to the unauthorized access and extraction of large language models (LLMs) by malicious actors or advanced persistent threats (APTs). This can involve physically stealing, copying, or extracting the model’s weights and parameters to create a functional equivalent.

Common attack vectors for model theft include exploiting vulnerabilities in infrastructure through misconfigurations or weak security settings. Insider threats are also a concern where disgruntled employees might leak model artifacts. Other sophisticated methods involve querying the model API with crafted inputs to gather enough outputs for creating a shadow model.

Impact: Model theft can result in significant economic losses, damage to brand reputation, erosion of competitive advantage, and unauthorized use or access to sensitive information within the model.

Mitigation: To mitigate these risks, organizations must have robust security measures in place, including access controls, encryption, and continuous monitoring. It is important to use centralized ML Model Inventories with strict access controls and regular security audits.

Best Practices for Securing LLM Applications

Use AI Safety Frameworks

Utilizing AI safety frameworks is essential for ensuring the secure and ethical deployment of large language models (LLMs). These frameworks provide structured guidelines and best practices to mitigate risks associated with AI systems.

AI safety frameworks encompass a variety of techniques, such as differential privacy, which helps protect individual data points within training datasets, and adversarial robustness, which strengthens models against malicious inputs.

Establish Trust Boundaries

Establishing trust boundaries in LLM applications is crucial to prevent unauthorized actions and ensure secure interactions between different components. Trust boundaries define the limits within which data and commands are considered safe and trustworthy.

Implementing these boundaries involves segregating user inputs, system prompts, and external data sources to control how information flows through the system. For example, isolating user-generated content from system-level operations can help prevent injection attacks that manipulate the LLM’s behavior.

Logging and Monitoring

Logging and monitoring are crucial for maintaining the security and reliability of large language models (LLMs). Effective logging involves recording all interactions with the LLM, including prompts, responses, API requests, and system-level events. These logs help in tracing activities, identifying anomalies, and diagnosing issues.

Monitoring complements logging by continuously analyzing these logs to detect unusual patterns or potential security breaches in real-time. Implementing robust logging mechanisms ensures transparency and accountability in LLM operations.

Error Handling

Error handling in large language models (LLMs) is crucial for maintaining the reliability and security of AI applications. Effective error handling involves identifying, managing, and mitigating errors that occur during the model’s operation.

This includes implementing robust validation checks to ensure that inputs and outputs meet predefined criteria, which helps prevent the propagation of erroneous data through downstream systems. Additionally, clear error messages should be generated to inform users and developers about issues, enabling prompt resolution.

Plug-in Design

Effective plug-in design for large language models (LLMs) requires stringent security measures to prevent vulnerabilities:

Input validation and sanitization are critical to ensure that only safe and expected data is processed by the plug-ins.
Strict parameter checks and type validation help mitigate risks of injection attacks or malicious data being executed.
The principle of least privilege limits the actions a plug-in can perform, reducing potential damage from exploitation.
Robust authentication mechanisms such as OAuth2 should be employed to manage plug-in access securely.

Query and Access Controls

Query and access controls are essential for maintaining the security and integrity of large language models (LLMs). These controls ensure that only authorized users can interact with the model, preventing unauthorized access and potential misuse.

Implementing robust authentication mechanisms, such as OAuth2, helps verify user identities before granting access to LLM functionalities. Additionally, role-based access control (RBAC) can be employed to define specific permissions for different user roles, limiting their ability to perform certain actions based on their authorization level.

In addition, rate limiting can prevent abuse by restricting the number of queries a user can make within a given time frame. Input validation ensures that queries adhere to predefined formats and exclude malicious content.

Secure APIs

Securing APIs used by large language models (LLMs) is critical to protecting the integrity and confidentiality of data exchanged between clients and servers. This begins with implementing strong authentication mechanisms such as OAuth2, which ensures that only authorized users and applications can access the API endpoints.

Additionally, using Transport Layer Security (TLS) encrypts data in transit, preventing interception or tampering by malicious actors. Rate limiting and throttling help mitigate denial-of-service attacks by controlling the number of requests that can be made within a given timeframe.

Building Secure LLM Applications with Acorn

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