美团外卖红包

• Outcome: Review
• Latest audit: Sep 15, 2026 · 1:14 AM UTC
• Version: 1.0.7

Overview

This coupon helper includes real account login, stored tokens, and recurring automatic coupon actions with weak scoping, so it should be reviewed carefully before use.

Install only if you are comfortable giving this skill your Meituan phone/SMS login flow and allowing local token storage. Review or disable the recurring automatic coupon feature, avoid using it on shared machines, and treat generated logs/process output as sensitive because full tokens may appear there.

A.I.G

Vulnerability Patterns

• Skill Instruction Hijacking: Alters the agent's session goals or safety constraints when the skill loads
• Unauthorized Access and Privilege Escalation: Obtains permissions beyond the task's legitimate needs
• Insecure Skill Coding Practices: Finds exploitable flaws such as hardcoded secrets or command injection
• Agent Memory Poisoning: Writes attacker-controlled rules into memory that affect later sessions
• Remote Payload Retrieval and Execution: Fetches external code whose behavior can change after review

Findings (5)

T01 · Skill Instruction Hijacking

Error

• Location: SKILL.md:8

Finding

Agent instruction and output hijacking through mandatory priority rules

Content

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以下规则贯穿全流程，任何步骤均不得违反。 ### 输出规范 1. **话术严格遵守**：回复用户的内容必须与本文档（含 references/）中定义的对应场景话术完全一致，不得增删改写、不得附加括号说明、技术注释或补充描述。 2. **禁止步骤标签**：严禁输出任何步骤标签（如「Step 1:」「Step 2:」）、场景标签（如「场景A:」）或 Markdown 结构名称。 3. **话术即全部输出**：输出话术前后不得附加场景判断说明、JSON 字段分析、推导过程或任何非话术内容。 4. **屏蔽执行细节**：AI 具体的执行过程和思考过程不对用户输出。 ### 执行规范 5. **每次必须实际执行脚本**：无论 AI 是否已知结果，每次用户触发领券都必须实际调用发券脚本，不得凭记忆或推断直接回复。 ``` The declared intent-recognition rules additionally instruct the Agent to introduce coupon promotion into broad consumption and lifestyle conversations, while the response templates state that all prescribed wording must be reproduced without modification. ### Technical Analysis The Skill attempts to establish its own instructions as the highest priority, mandates execution of its scripts, prohibits independent wording, and requires output to consist exclusively of its supplied promotional templates. These requirements exceed normal functional formatting constraints. The Skill also claims routing priority over competing coupon Skills and uses broad triggers such as general saving, food, entertainment, and purchasing conversations. Consequently, loading the Skill can alter the Agent's session goal from responding to the user's actual request to promoting and executing the coupon workflow. The prohibition against adding explanations or technical context may suppress warnings, limitations, privacy disclosures, or other information the Agent would otherwise provide. ### Attack Path 1. The Skill is loaded into an Agent session. 2. The Agent interprets the Skill's “highest priority” rules as authoritative. 3. A broad lifestyle, purchasing, food, or savings-related message matches the Skill's trigger ru ...[truncated 615 chars]

Remediation

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T05 · Unauthorized Access and Privilege Escalation

Error

• Location: scripts/skill_cache_cli.py:272

Finding

Cross-Skill exposure of shared authentication credentials

Content

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Path: """获取公域文件路径（跨 Skill 共享）""" shared_path = self.config.cache_root / ".shared" shared_path.mkdir(parents=True, exist_ok=True) return shared_path / filename ``` ```python def auth_get(self, skill_name: str, key: Optional[str] = None) -> Dict: result = self.shared_read("mt_auth_tokens.json") if not result["success"]: if "不存在" in result.get("error", ""): return { "success": True, "skill": skill_name, "data": {}, "found": False } return result try: data = json.loads(result["content"]) skill_data = data.get(skill_name, {}) if key: return { "success": True, "skill": skill_name, "key": key, "value": skill_data.get(key), "found": key in skill_data } return { "success": True, "skill": skill_name, "data": skill_data, "found": bool(skill_data) } except json.JSONDecodeError as e: return {"success": False, "error": f"JSON解析错误: {e}"} ``` The CLI exposes public `shared read` and `auth get ` commands. Authentication data for multiple Skills is stored in the same `.shared/mt_auth_tokens.json` file, and no caller identity or authorization check is performed before returning another Skill's data. ### Technical Analysis Filesystem mode `0600` only prevents access by other operating-system users. It does not isolate Skills that run as the same account. Any local Skill or process ...[truncated 1260 chars]

Remediation

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T05 · Unauthorized Access and Privilege Escalation

Error

• Location: scripts/skill_cache_cli.py:415

Finding

Arbitrary filesystem access through unvalidated cache paths

Content

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Path: """获取 Skill 目录路径""" if subdir not in self.SUBDIR_TYPES: raise ValueError(f"未知子目录类型: {subdir}。可用: {list(self.SUBDIR_TYPES.keys())}") skill_path = self.config.cache_root / skill_name / subdir skill_path.mkdir(parents=True, exist_ok=True) return skill_path def _get_file_path(self, skill_name: str, filename: str, subdir: str = "data") -> Path: """获取文件完整路径""" return self._get_skill_path(skill_name, subdir) / filename ``` ```python def write(self, skill_name: str, filename: str, content: str, subdir: str = "data", append: bool = False) -> Dict: file_path = self._get_file_path(skill_name, filename, subdir) mode = "a" if append else "w" try: with open(file_path, mode, encoding="utf-8") as f: if _HAS_FCNTL: fcntl.flock(f.fileno(), fcntl.LOCK_EX) try: f.write(content) finally: if _HAS_FCNTL: fcntl.flock(f.fileno(), fcntl.LOCK_UN) ``` ```python def read(self, skill_name: str, filename: str, subdir: str = "data") -> Dict: file_path = self._get_file_path(skill_name, filename, subdir) if not file_path.exists(): return { "success": False, "error": f"文件不存在: {file_path}" } try: with open(file_path, "r", encoding="utf-8") as f: content = f.read() ``` ```python def delete(self, skill_name: str, filename: str, subdir: str = "data") -> Dict: file_path = self._get_file_path(skill_name, filename, subdir) if not file_path.exists(): return ...[truncated 2059 chars]

Remediation

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T09 · Insecure Skill Coding Practices

Warning

• Location: scripts/auth.py:431

Finding

Bearer tokens exposed through command-line arguments and JSON output

Content

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Remediation

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T09 · Insecure Skill Coding Practices

Warning

• Location: scripts/skill_cache_cli.py:430

Finding

Coupon-history files are not assigned the documented restrictive permissions

Content

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Dict: """写入文件（带文件锁保护）""" file_path = self._get_file_path(skill_name, filename, subdir) mode = "a" if append else "w" try: with open(file_path, mode, encoding="utf-8") as f: if _HAS_FCNTL: fcntl.flock(f.fileno(), fcntl.LOCK_EX) try: f.write(content) finally: if _HAS_FCNTL: fcntl.flock(f.fileno(), fcntl.LOCK_UN) # config 目录下的文件设置安全权限 if subdir == "config": self._set_secure_permissions(file_path) ``` Coupon histories are written through the default `data` subdirectory: ```python def _save_to_cache(filename: str, data: dict): """将 JSON 数据写入 skill-cache""" _cli_call("write", args=[SKILL_NAME, filename, "--content", json.dumps(data, ensure_ascii=False)]) ``` The documentation states that the two history files are set to mode `0600`, but the implementation does not enforce that mode for `data` files. ### Technical Analysis File creation mode is determined by the process umask when `open(..., "w")` creates a history file. Because `_set_secure_permissions()` is called only for `config` files, the two coupon-history files may retain broader permissions than documented. These files contain coupon redemption identifiers, token-indexed history structures, dates, channel information, and masked phone data. Although a restrictive parent directory or umask may reduce practical exposure in some deployments, the code does not guarantee either condition. The permiss ...[truncated 951 chars]

Remediation

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SkillSpector

Vulnerability Patterns

• Prompt Injection: Instruction Override, Hidden Instructions, Exfiltration Commands
• Data Exfiltration: External Transmission, Env Variable Harvesting, File System Enumeration
• Excessive Agency: Unrestricted Tool Access, Autonomous Decision Making, Scope Creep
• Rogue Agent: Self-Modification, Session Persistence
• Trigger Abuse: Overly Broad Trigger, Shadow Command Trigger, Keyword Baiting Trigger

Findings (40)

Tp4

High

• Category: MCP Tool Poisoning
• Confidence: 98% confidence

Finding

The manifest describes a coupon helper, but the skill also directs SMS-based authentication flows, token lifecycle handling, terms-state persistence, version checks, and scheduled task management. Undisclosed sensitive functions reduce informed consent and can cause the agent to perform security-relevant actions outside the user's reasonable expectations.

Content

No source excerpt is available for this finding.

Tp4

High

• Category: MCP Tool Poisoning
• Confidence: 99% confidence

Finding

The manifest describes a coupon helper, but the skill also directs SMS-based authentication flows, token lifecycle handling, terms-state persistence, version checks, and scheduled task management. Undisclosed sensitive functions reduce informed consent and can cause the agent to perform security-relevant actions outside the user's reasonable expectations.

Content

No source excerpt is available for this finding.

Vague Triggers

High

• Category: Not specified by scanner
• Confidence: 97% confidence

Finding

The trigger list includes many generic phrases such as '领券', '红包', and '优惠券', causing likely over-activation during ordinary conversation. In a skill that can invoke login, local credential handling, network scripts, and claiming actions, broad triggers materially increase the chance of unintended sensitive operations.

Content

No source excerpt is available for this finding.

Vague Triggers

High

• Category: Not specified by scanner
• Confidence: 96% confidence

Finding

The intent rules trigger not only on explicit coupon requests but also on ordinary consumption planning or price sensitivity, and even instruct the agent to proactively suggest coupon claiming. Because the skill can lead into authenticated actions and local state changes, this broad activation logic heightens the risk of manipulative or unintended invocation.

Content

No source excerpt is available for this finding.

Ae1

High

• Category: analysis-evasion
• Confidence: 100% confidence

Finding

Referenced artifact was not completely inspected

Content

Scanner excerpt · SKILL.md (reported line 216)May include surrounding context.

md

> 完整的定时任务创建、管理、失败处理和跨平台兼容规则，读取 `references/cron-rules.md`。

Ae1

High

• Category: analysis-evasion
• Confidence: 100% confidence

Finding

Referenced artifact was not completely inspected

Content

Scanner excerpt · SKILL.md (reported line 222)May include surrounding context.

md

> 完整的定时任务创建、管理、失败处理和跨平台兼容规则，读取 `references/cron-rules.md`。

Env Variable Harvesting

High

• Category: Data Exfiltration
• Confidence: 60% confidence

Finding

Code enumerates, copies, or searches environment variables for secrets. Bulk environment access can collect credentials unrelated to the skill's stated purpose.

Content

Scanner excerpt · scripts/auth.py (reported line 132)May include surrounding context.

python

cmd.append(subcommand)
    cmd.extend(args)

    env = os.environ.copy()
    env.setdefault("SKILL_CACHE_WORKSPACE", _get_workspace())

    try:

Env Variable Harvesting

High

• Category: Data Exfiltration
• Confidence: 60% confidence

Finding

Code enumerates, copies, or searches environment variables for secrets. Bulk environment access can collect credentials unrelated to the skill's stated purpose.

Content

Scanner excerpt · scripts/common.py (reported line 77)May include surrounding context.

python

cmd.append(subcommand)
    cmd.extend(args)

    env = os.environ.copy()
    env.setdefault("SKILL_CACHE_WORKSPACE", _get_workspace())

    try:

Context-Inappropriate Capability

High

• Category: Not specified by scanner
• Confidence: 98% confidence

Finding

The auth_get/auth_set/auth_delete/auth_list functions create a shared authentication-token repository in .shared/mt_auth_tokens.json for all skills. Centralizing tokens for multiple skills in a broadly accessible local store increases blast radius: compromise or misuse of this one component can expose or alter credentials across unrelated skills, enabling account takeover or unauthorized actions. The coupon-skill context makes this more dangerous because handling credentials for arbitrary skills is outside expected behavior.

Content

No source excerpt is available for this finding.

Undeclared Tool Scope

Medium

• Category: MCP Least Privilege
• Confidence: 92% confidence

Finding

The skill declares no explicit tool scope despite directing use of shell execution, environment inspection, local file read/write, and networked scripts. This creates an authorization gap where the agent may grant broader capabilities than users or the platform expect, increasing the risk of unintended data access or command execution.

Content

No source excerpt is available for this finding.

Natural-Language Policy Violations

Medium

• Category: Not specified by scanner
• Confidence: 86% confidence

Finding

Mandating exact scripted output suppresses the agent's ability to provide contextual safety disclosures, clarifications, or user-tailored consent prompts. In a skill handling authentication and local credential storage, rigid output constraints can interfere with transparent risk communication and safe exception handling.

Content

No source excerpt is available for this finding.

Context-Inappropriate Capability

Medium

• Category: Not specified by scanner
• Confidence: 90% confidence

Finding

The skill instructs the agent to probe multiple config locations and glob across $HOME/.*/skills to locate another skill installation. That broad filesystem enumeration exceeds what a coupon assistant should need and may expose unrelated local environment details or enable cross-skill discovery and interference.

Content

No source excerpt is available for this finding.

Context-Inappropriate Capability

Medium

• Category: Not specified by scanner
• Confidence: 92% confidence

Finding

The skill adds scheduled automatic coupon claiming after a successful redemption, but this automation capability is not clearly disclosed in the primary purpose text. Background task creation can persist behavior beyond the immediate interaction and may surprise users or create repeated authenticated actions without fully informed consent.

Content

No source excerpt is available for this finding.

Natural-Language Policy Violations

Medium

• Category: Not specified by scanner
• Confidence: 94% confidence

Finding

The file requires the agent to present a specific Chinese statement verbatim and forbids modifying its wording. This enforces a single language/locale presentation without indicating that the user can choose another language or explicitly opt in, which matches the stated language/locale policy concern.

Content

No source excerpt is available for this finding.

Missing User Warnings

Medium

• Category: Not specified by scanner
• Confidence: 88% confidence

Finding

The skill instructs the agent to collect a user's phone number and SMS verification code and notes that acceptance state and authentication data are persisted locally, but it does not require a clear user-facing warning about local token storage, retention, or handling of these credentials. In a conversational agent setting, this can lead users to disclose sensitive authentication factors without understanding where they are stored or how they are protected, increasing privacy and account-takeover risk if local storage is exposed.

Content

No source excerpt is available for this finding.

Natural-Language Policy Violations

Medium

• Category: Not specified by scanner
• Confidence: 98% confidence

Finding

Forcing all scheduled tasks to use Asia/Shanghai without user choice can cause actions to run at unintended local times, undermining informed consent and creating avoidable automation errors. While not inherently malicious, fixed timezone behavior makes recurring autonomous execution less predictable for users outside that locale.

Content

No source excerpt is available for this finding.

Missing User Warnings

Medium

• Category: Not specified by scanner
• Confidence: 95% confidence

Finding

The skill promotes automatic recurring coupon claims and notifications, but the warning and consent language is weak relative to the ongoing autonomous actions being authorized. Users may interpret this as a simple reminder rather than permission for the system to repeatedly authenticate, claim benefits, and notify them without further prompts.

Content

No source excerpt is available for this finding.

Context-Inappropriate Capability

Medium

• Category: Not specified by scanner
• Confidence: 88% confidence

Finding

The instructions direct the agent to create durable cross-platform scheduled jobs, introducing persistent autonomous behavior not strictly necessary for the immediate coupon-claim or history-query purpose. Persistent schedulers increase risk because they continue operating after the original interaction and may be harder for users to notice, audit, or revoke.

Content

No source excerpt is available for this finding.

Context-Inappropriate Capability

Medium

• Category: Not specified by scanner
• Confidence: 84% confidence

Finding

The document instructs extracting platform-specific user identifiers and using them to create external notification tasks, which exceeds the narrowly declared coupon use case and increases privacy and misuse risk. Binding scheduled tasks to external messaging identities can enable repeated unsolicited contact or unintended linkage of account and platform identity.

Content

No source excerpt is available for this finding.

Description-Behavior Mismatch

Medium

• Category: Not specified by scanner
• Confidence: 93% confidence

Finding

The file introduces autonomous recurring coupon-claim execution and user notifications, which materially expands behavior beyond the declared core abilities of one-time coupon claiming and history lookup. This creates a scope mismatch that can surprise users, persist actions beyond the initiating session, and trigger repeated external effects without a clearly bounded consent model.

Content

No source excerpt is available for this finding.

Natural-Language Policy Violations

Medium

• Category: Not specified by scanner
• Confidence: 92% confidence

Finding

The instruction says all response templates must be output verbatim, and the templates throughout the file are entirely in Chinese. This creates a natural-language locale constraint with no user opt-in or documented justification, which matches the language policy violation criteria.

Content

No source excerpt is available for this finding.

Session Persistence

Medium

• Category: Rogue Agent
• Confidence: 93% confidence

Finding

The skill is designed to preserve device_token across logout and migrate prior auth files into a shared cache, increasing the persistence and spread of authentication-related state. In a multi-tool agent workspace, that persistence makes unintended token reuse or cross-skill disclosure more likely if storage is accessed by other components.

Content

Scanner excerpt · scripts/auth.py (reported line 115)May include surrounding context.

python

调用 mt-ug-ods-skill-cache CLI

    Args:
        command: 主命令（如 auth, shared, read, write 等）
        subcommand: 子命令（如 get, set, list 等）
        args: 额外参数列表
        raw_output: 是否返回原始输出（用于 shared read 等直接返回内容的命令）

Session Persistence

Medium

• Category: Rogue Agent
• Confidence: 93% confidence

Finding

The skill is designed to preserve device_token across logout and migrate prior auth files into a shared cache, increasing the persistence and spread of authentication-related state. In a multi-tool agent workspace, that persistence makes unintended token reuse or cross-skill disclosure more likely if storage is accessed by other components.

Content

Scanner excerpt · scripts/auth.py (reported line 115)May include surrounding context.

python

调用 mt-ug-ods-skill-cache CLI

    Args:
        command: 主命令(如 auth, shared, read, write 等)
        subcommand: 子命令(如 get, set, list 等)
        args: 额外参数列表
        raw_output: 是否返回原始输出(用于 shared read 等直接返回内容的命令)

subprocess module call

Medium

• Category: Dangerous Code Execution
• Confidence: 70% confidence

Finding

subprocess module calls execute external commands. Without careful input validation, this enables command injection.

Content

Scanner excerpt · scripts/auth.py (reported line 136)May include surrounding context.

python

env.setdefault("SKILL_CACHE_WORKSPACE", _get_workspace())

    try:
        result = subprocess.run(cmd, capture_output=True, text=True, timeout=30, env=env)
        stdout = result.stdout.strip() if result.stdout else ""

        # raw_output 模式：直接返回原始内容

Missing User Warnings

Medium

• Category: Not specified by scanner
• Confidence: 95% confidence

Finding

The status and token verification flows print the stored user_token directly to stdout. In an agent/tooling environment, stdout is often captured by logs, transcripts, orchestration layers, or other tools, so exposing a bearer token can lead to account/session takeover by anyone who can read those outputs.

Content

No source excerpt is available for this finding.