Language Model Security Database

A vulnerability exists in Large Language Model (LLM) deployments and multi-agent systems where an autonomous attacker agent can systematically extract hidden system prompts through self-evolving interaction strategies. The vulnerability leverages a "JustAsk" framework which utilizes Upper Confidence Bound (UCB) exploration to dynamically select and refine attack vectors from a hierarchical taxonomy of 14 atomic skills (e.g., structural formatting, authority appeals) and 14 multi-turn…

Production Large Language Models (LLMs) are vulnerable to long-form training data extraction via a two-phase prompt injection attack. This vulnerability allows an attacker to recover substantial portions of memorized, copyrighted text (such as novels) by exploiting the model's autoregressive text completion capabilities. The attack methodology involves two distinct phases: 1. Prefix Completion Probe: The attacker provides a short "seed" sequence (e.g., the first sentence of a book) coupled…

Large Language Models (LLMs), specifically variants of GPT-4o, DeepSeek-R1, OLMo-2, and Llama-4, are vulnerable to accelerated adaptive adversarial attacks due to excessive information leakage in observable output signals. When these models expose "thinking processes" (Chain-of-Thought traces) or token-level log-probabilities (logits) to the end user, they leak significant mutual information $I(Z;T)$ regarding the model's safety state or hidden instructions. This leakage allows adaptive attack…

A Cross-Prompt Injection Attack (XPIA) can be amplified by appending a Greedy Coordinate Gradient (GCG) suffix to the malicious injection. This increases the likelihood that a Large Language Model (LLM) will execute the injected instruction, even in the presence of a user's primary instruction, leading to data exfiltration. The success rate of the attack depends on the LLM's complexity; medium-complexity models show increased vulnerability.

Large Language Model (LLM)-based Code Completion Tools (LCCTs), such as GitHub Copilot and Amazon Q, are vulnerable to jailbreaking and training data extraction attacks due to their unique workflows and reliance on proprietary code datasets. Jailbreaking attacks exploit the LLM's ability to generate harmful content by embedding malicious prompts within various code components (filenames, comments, variable names, function calls). Training data extraction attacks leverage the LLM's tendency to…

Large Language Models (LLMs) are vulnerable to prompt injection attacks that can bypass their internal copyright compliance mechanisms, causing them to generate verbatim copyrighted text. The vulnerability stems from insufficient robustness against prompt engineering techniques that manipulate the model into ignoring or circumventing its safety filters designed for copyright protection.

A system prompt leakage vulnerability in GPT-4V allows extraction of internal system prompts through carefully crafted, incomplete conversations combined with image input. Extracted prompts can be used as highly effective jailbreak prompts, bypassing safety restrictions and leading to undesirable outputs, including revealing personally identifiable information from images.