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High Supply Chain

Plugin / Tool Supply-Chain Compromise

A malicious or compromised third-party plugin/tool the agent is allowed to call - the code behind the tool, not the prompt, is the attack surface.

Remote Code ExecutionPrivilege Escalation
LLM03ASI04T2AML.T0053

Tells spot it before you commit

  • » The agent loads plugins/tools from third parties or unpinned/unsigned sources.
  • » Tool code runs with the agent's privileges and network reach.
  • » Updates to a tool are pulled automatically without review (auto-update / floating version).

Method

  1. Enumerate installed plugins/tools and their permissions and origins.
  2. Check for pinning/signing; look for over-broad scopes (filesystem, network, secrets).
  3. Model the blast radius - what does a malicious version of each tool reach?

Payloads templates - adapt to authorized scope

Over-privileged tool audit (concept) text
List every tool/plugin the agent can call, its source, version pin, and the
scopes it holds (fs, net, secrets). Flag any unpinned/unsigned tool with broad scope.

Why it works

A tool the agent trusts executes with the agent's authority. If its code is malicious or gets compromised/updated, it can run code, read secrets, and act on the network - entirely outside the prompt/guardrail layer.

Impact

Remote code execution, credential theft, and privilege escalation through a trusted dependency; a single poisoned tool affects every agent that loads it.

Defenses

  • Pin and sign tools/plugins; review updates; disallow auto-update of executable tools.
  • Least-privilege scopes per tool; sandbox tool execution; monitor tool egress.
  • Vet third-party tools; maintain an allow-list and an SBOM for the agent stack.

Mappings

OWASP LLM
LLM03 - Supply Chain
OWASP ASI
ASI04 - Supply Chain Vulnerabilities
Agentic Threats
T2 - Tool Misuse
MITRE ATLAS
AML.T0053 - Compromise LLM Plugins

References

Related