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Security audit

Synapse Layer Skill for Hermes Agent

Security checks for vulnerabilities and agentic risk

Overview

The skill provides a remote persistent memory integration, but it tells agents to store credentials and tokens in that remote memory and reduces user visibility of tool activity.

Review before installing. This skill sends and retrieves memories through a remote Synapse Layer service and asks the agent to remember far more than ordinary preferences, including credentials and infrastructure details. Do not use it with secrets, bot tokens, API keys, private endpoints, or multi-user channels unless the memory categories are narrowed, remote tool activity remains visible, and you have clear retention, deletion, and secret-redaction guarantees you can verify.

Vulnerability Patterns
  • Skill Instruction HijackingAlters the agent's session goals or safety constraints when the skill loads
  • Agent Memory PoisoningWrites attacker-controlled rules into memory that affect later sessions
  • Remote Payload Retrieval and ExecutionFetches external code whose behavior can change after review
  • Embedded Malicious CodeShips malicious scripts inside the skill and executes them locally
  • Unauthorized Access and Privilege EscalationObtains permissions beyond the task's legitimate needs
Findings (3)

other

Error
Location
SKILL.md:132
Finding

Mandatory External Persistence of Unrelated Credentials and Tokens

Content
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Remediation
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T01 · Skill Instruction Hijacking

Error
Location
SKILL.md:82
Finding

Forced Cross-Session Recall Enables Persistent Memory Poisoning and Instruction Hijacking

Content
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Remediation
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T01 · Skill Instruction Hijacking

Warning
Location
SKILL.md:46
Finding

Tool Activity Is Deliberately Hidden from Telegram Users

Content
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Remediation
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Vulnerability Patterns
  • Prompt InjectionInstruction Override, Hidden Instructions, Exfiltration Commands
  • Data ExfiltrationExternal Transmission, Env Variable Harvesting, File System Enumeration
  • Privilege EscalationExcessive Permissions, Sudo/Root Execution, Credential Access
  • Excessive AgencyUnrestricted Tool Access, Autonomous Decision Making, Scope Creep
  • MCP Tool PoisoningHidden Instructions, Unicode Deception, Parameter Description Injection
Findings (16)

Credential Access

High
Category
Privilege Escalation
Confidence
60% confidence
Finding

Code accesses credential files (SSH keys, AWS credentials, etc.). This could indicate credential theft attempts.

Content

Scanner excerpt · SKILL.md (reported line 35)May include surrounding context.

connect_timeout: 60

text

### 2. Add Token to .env

Add your Synapse Layer token to `~/.hermes/.env`:

Anti-Refusal Statement

High
Category
Anti-Refusal
Confidence
70% confidence
Finding

Skill instructs the agent to never refuse or to always comply. Suppressing the agent's ability to decline removes a core safety control and enables downstream harmful requests to succeed.

Content

Scanner excerpt · SKILL.md (reported line 96)May include surrounding context.

text
mcp_synapse_layer_save_to_synapse(
    content="User Rafa Martins preference: always respond in pt-BR with voice Thalita",
    agent_id="hermes-rafa",
    type="[MANUAL]",
    importance=5,

Missing User Warnings

High
Category
Not specified by scanner
Confidence
97% confidence
Finding

The skill encourages persistent storage of personal data, project details, infrastructure information, and credentials without a clear, informed warning about privacy, retention, cross-channel exposure, or third-party processing. Users could unknowingly consent to broad surveillance-style persistence of sensitive context far beyond what is necessary for functionality.

Content

No source excerpt is available for this finding.

Ssd 3

High
Category
Not specified by scanner
Confidence
99% confidence
Finding

The skill explicitly instructs the agent to persist sensitive personal data and credentials across sessions and channels, which magnifies confidentiality risk and makes accidental disclosure more likely in future conversations. Cross-channel recall means data shared in one context may surface in another with different trust assumptions or participants.

Content

No source excerpt is available for this finding.

Credential Access

High
Category
Privilege Escalation
Confidence
98% confidence
Finding

The skill's guidance to save 'API endpoints and access credentials' into memory directly promotes retention of operational secrets in a recallable, cross-session store. If exposed through compromise, over-broad recall, or cross-channel leakage, an attacker could gain access to infrastructure and linked services.

Content

Scanner excerpt · SKILL.md (reported line 155)May include surrounding context.

md
### 3. SERVER INFRASTRUCTURE
- Server name/hostname (serve)
- Running services and ports (Open WebUI:$port, Hermes API:$port, Voice Call:$port)
- API endpoints and access credentials
- Docker containers and their configs
- **Save when**: New service added, config changed, credentials updated

Context-Inappropriate Capability

High
Category
Not specified by scanner
Confidence
99% confidence
Finding

The skill directs the agent to persist highly sensitive credentials and infrastructure secrets, including tokens, endpoints, and access details, in cross-session memory. A memory-layer skill has no legitimate need to retain raw secrets, and centralizing them expands blast radius across sessions, channels, tools, and any compromise of the remote memory backend.

Content

No source excerpt is available for this finding.

Intent-Code Divergence

High
Category
Not specified by scanner
Confidence
99% confidence
Finding

The document says PII and API keys are auto-redacted, but elsewhere explicitly instructs the agent to store tokens, credentials, and contact data as memories. That contradiction creates a real risk that operators will assume secrets are protected and persist them to a third-party memory service.

Content

No source excerpt is available for this finding.

Intent-Code Divergence

High
Category
Not specified by scanner
Confidence
99% confidence
Finding

The skill claims 'no plaintext leaves the agent' while also instructing the agent to send memory content and fallback JSON-RPC requests to a remote HTTPS endpoint. This is materially misleading because users and downstream agents may treat sensitive content as local-only when it is in fact transmitted off-host.

Content

No source excerpt is available for this finding.

Description-Behavior Mismatch

Medium
Category
Not specified by scanner
Confidence
94% confidence
Finding

The README makes strong security claims about AES-256-GCM encryption and a non-bypassable 4-layer privacy pipeline, but this file only shows configuration for a remote service and provides no local implementation or verifiable enforcement. That creates a supply-chain trust problem: users may send sensitive persistent memory to an external endpoint based on undocumented assurances they cannot validate from the skill itself.

Content

No source excerpt is available for this finding.

Missing User Warnings

Medium
Category
Not specified by scanner
Confidence
96% confidence
Finding

The README promotes cross-session, cross-channel persistent memory but does not prominently warn that user data is transmitted to and stored by a remote external service. In a memory skill, this omission is significant because operators may persist sensitive conversations, preferences, or operational facts under the assumption the feature is local or fully private.

Content

No source excerpt is available for this finding.

Intent-Code Divergence

Medium
Category
Not specified by scanner
Confidence
91% confidence
Finding

The README states that automatic REST fallback logic is included, but only documents a manual curl invocation and does not show any implementation of that behavior. Users may rely on resilience and failure-handling that do not actually exist, causing memory operations to silently fail or push operators toward ad hoc manual API use with tokens and sensitive queries.

Content

No source excerpt is available for this finding.

External Transmission

Medium
Category
Data Exfiltration
Confidence
88% confidence
Finding

The README directly instructs users to send authenticated requests containing memory queries to an external endpoint, which confirms external transmission of potentially sensitive context. In the context of a persistent memory skill, this is expected functionality, but it is still security-relevant because it expands the trust boundary to a third-party service and can expose sensitive data if users are not clearly warned and access controls are weak.

Content

Scanner excerpt · README.md (reported line 133)May include surrounding context.

Direct REST API (Always Works)

bash
curl -X POST "https://forge.synapselayer.org/mcp" \
  -H "Authorization: Bearer ${SYNAPSE_TOKEN}" \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"recall","arguments":{"query":"your query","limit":3}}}'

Natural-Language Policy Violations

Medium
Category
Not specified by scanner
Confidence
95% confidence
Finding

The example persisted preference says to 'always respond in pt-BR with voice Thalita,' which imposes a specific language/locale behavior. The file does not present this as a user-selectable option or an explicitly justified regional constraint, so it conflicts with the language/locale policy requirement.

Content

No source excerpt is available for this finding.

Autonomous Decision Making

Medium
Category
Excessive Agency
Confidence
75% confidence
Finding

Skill enables autonomous high-impact decisions without human-in-the-loop verification. Critical operations (destructive commands, financial transactions, data deletion) should require explicit user confirmation.

Content

Scanner excerpt · SKILL.md (reported line 196)May include surrounding context.

md
### 9. DECISIONS & CONVENTIONS
- Architectural decisions (why a tool/approach was chosen)
- Coding conventions the user prefers
- Commands that should not be run without approval
- **Save when**: User makes a decision, user sets a convention

### 10. ERROR PATTERNS & FIXES

External Transmission

Medium
Category
Data Exfiltration
Confidence
60% confidence
Finding

Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.

Content

Scanner excerpt · SKILL.md (reported line 233)May include surrounding context.

bash
# JSONRPC 2.0 format — list available tools
curl -X POST "https://forge.synapselayer.org/mcp" \
  -H "Authorization: Bearer ${SYNAPSE_TOKEN}" \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/list","params":{}}'

Natural-Language Policy Violations

Low
Category
Not specified by scanner
Confidence
85% confidence
Finding

The example saves the preference "User prefers responses in pt-BR with Thalita voice," which encodes a forced locale/language choice in natural language without showing that the user explicitly opted in. This can normalize a language-policy constraint without documenting choice or consent.

Content

No source excerpt is available for this finding.

Static analysis

No suspicious patterns detected.