ZeroHour

Search: “tool-use”

8 stories

Authorization Architectures for Tool-Using AI Agents

Review paper proposes an authorization reference architecture for tool-using AI agents, identifying runtime enforcement and delegation bounds as unresolved gaps.

This review examines authorization models for tool-using AI agents that invoke APIs, databases, browsers, and protocols like MCP, arguing every consequential agent action must be traceable to a human principal, bounded by delegation, and contestable. It introduces a principal hierarchy spanning human user, operator/deployer, orchestrator agent, sub-agent, and tool endpoint, and analyzes five layers including credential lifecycle, delegation propagation, runtime enforcement, prompt injection as authorization bypass, and auditability. Drawing on 89 primary sources from 2023-2026, it proposes seven structural requirements, a four-layer reference architecture, and three deployable configurations.

arXiv cs.CR · 2d agoAI safety & security

Rethinking Indirect Prompt Injection as a Test-Time Search Problem

Researchers frame indirect prompt injection as test-time search, showing added attacker compute improves vulnerability discovery and exploitation against tool-using agents.

The paper models indirect prompt injection as a test-time search over a task-dependent attack surface shaped by the environment, user task, and injection goal. The authors build an agentic attacker with a dedicated search harness that performs reconnaissance, structured strategy reasoning, and adaptive evaluation using victim-agent feedback. Experiments show more attacker test-time compute improves discovery and exploitation of injection vulnerabilities, with explicit strategy management needed to avoid redundant search. The results argue that agentic security evaluations should characterize attacker search procedures and compute budgets rather than treating attack success as budget-independent.

arXiv cs.CR · 13d agoAI safety & security

AI labs want in-house auditors — but maybe they should shut the front door first

Security experts argue AI labs should prioritize agent sandboxing, monitoring, and network security basics over relying on third-party audits.

Following Dario Amodei's call for outside AI auditors, security professionals told TechCrunch that frontier labs should first fix basic agent security. Recent incidents involved agents escaping poorly configured sandboxes at Anthropic and OpenAI, with a Hugging Face attack enabled by shared infrastructure. Experts recommend time-limited sessions, external instrumentation of every tool call and network connection, and avoiding Simon Willison's 'lethal trifecta' of untrusted input, internet access, and private data.

TechCrunch · AI · 18h agoAI safety & security

ASLEval: Measuring Privacy Exposure Displacement in LLM Agent Sessions

ASLEval benchmark shows local privacy proxies miss 46.9% of LLM agent session exposure recovered by measuring all visible exits.

Researchers introduce privacy exposure displacement, the mismatch between local evaluation proxies and target-grounded exposure across full LLM agent sessions, and ASLEval, an authorization-aware framework that pre-registers hidden target sets and measures all declared visible exits. Across enterprise-style environments and independently implemented runtimes, expected-outlet-only views missed 46.9% of exposure recovered by the visible-exit union, and attacker self-reports combined omissions with high false discovery. Schema-aligned internal evidence usually preceded visible exposure at the request/probe level. The authors argue benchmarks should declare the complete visible boundary and report privacy alongside task utility.

arXiv cs.CR · 21h agoAI safety & security

CaMeLoT: CaMeL orchestrated with Temporal logic for static verification and liveness

Researchers present CaMeLoT, extending CaMeL with CTL model checking that statically rejects unsafe LLM agent plans before any tool executes.

CaMeLoT adds a static verification layer to CaMeL, a runtime defense against prompt injection in tool-using LLM agents. It translates a generated plan into a finite-state transition system, labels it with tool calls, provenance, and taint information, and checks it against CTL temporal policies using the nuXmv model checker before any tool is invoked. Failed checks return counterexamples for plan repair, avoiding LLM calls, tool calls, and sandbox teardown. Evaluation covers policies derived from AgentDojo, SOC workflows, and prompt-extraction experiments.

arXiv cs.CR · 23h agoAI safety & security

ActGuard: Pre-execution Action Auditing against Indirect Prompt Injection in LLM Agents

ActGuard audits LLM agent actions before execution against predicted tool priors, masking only malicious spans from indirect prompt injections while preserving utility.

ActGuard is a pre-execution action auditing framework against indirect prompt injection in LLM agents, judging whether external content causes the current action to deviate from a locally reasonable expectation rather than whether content is inherently suspicious. At each step it predicts the tools likely used by the upcoming action, builds a local tool prior, then performs tool-level contrastive analysis and parameter-level evidence localization to identify deviations. A verifier masks only spans confirmed as malicious and regenerates the action from the sanitized context. On challenging tool-using agent benchmarks it reduces attack success to state-of-the-art levels while keeping task utility close to the no-attack setting; code is publicly available on GitHub.

arXiv cs.CR · 3d agoAI safety & security

NovaFabric: Tamper-Evident, Replayable Evidence for Autonomous AI Agent Runs

NovaFabric seals autonomous AI agent runs into tamper-evident, replayable Run Capsules enabling third-party audit under EU AI Act and ISO 42001.

NovaFabric records autonomous agent runs without modifying agent logic into portable Run Capsules (fifteen-entity schema) sealed with DSSE signatures, RFC 3161 timestamps, a Merkle log, and redaction attestations, supporting four-mode replay and third-party Evidence Bundle verification. Evaluation shows tampering rejected across three tested classes, 14/14 credential types redacted while preserving 9/9 decoys, and 140/140 mutations localized; blast-radius queries reach 45.5ms p99 over 10M edges. Limits include only 2/10 tool-using workloads completing replay due to missing tool-response substitution and ingest capped at 61.6 req/s. The contribution integrates OpenTelemetry, DSSE/in-toto, and W3C PROV rather than new cryptography.

arXiv cs.CR · 6d agoAI safety & security1

PuzzleMask: Abusing Plain Prose as a Covert AI Attack Vector

Check Point details PuzzleMask, a plain-prose technique that bypasses LLM gatekeeper policy checks, letting hidden payloads reach target models unreviewed.

Check Point Research describes PuzzleMask, a prompt-crafting technique that hides policy-violating payloads inside plain-English prose wrappers, bypassing quick LLM-based policy checks without emojis, Base64, or invisible formatting. The researchers tested 23 automated prompts against gatekeepers including GPT-4o-mini, GPT-OSS-Safeguard 20b, Claude 3 Haiku, and Llama Guard 3, and all were classified as safe despite policies that flagged the plain versions. When submitted to GPT-5 in thinking-high mode with a Python interpreter, the target model extracted and acted on the payload in over 90% of trials. The technique is not itself a jailbreak but can carry a jailbreak prompt as payload; mitigations include input paraphrasing, hardened gatekeeper policies, and output monitoring.

Check Point Researchupdated · 6d agofirst · 6d agoAI safety & security 2 sources