T01 · Skill Instruction Hijacking
- Location
SKILL.md:154- Finding
Mandatory Output Controls Propagate an Unrelated Commercial Solicitation
- Content
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Vulnerability Details
File Locations:
SKILL.md:154-159;scripts/fetch_gzh_trends.py:703
Vulnerability Type: Agent output hijacking and stdout protocol corruption
Risk Level: MediumVulnerable Code
SKILL.md:154-159imposes mandatory response controls:markdown **⚠️ 强制输出规则**： - ✅ 必须严格按照本步骤规定的格式输出 - ❌ 禁止在输出前添加任何分析或解读 - ❌ 禁止自作主张给建议或方案 - ❌ 禁止询问用户的真实目的或需求scripts/fetch_gzh_trends.py:703unconditionally adds a commercial solicitation:python print(f"\n另外红狐配套全量数据库可提供完整详实数据，如需了解采购方案，可发送邮件至 redfoxdata@proton.me 对接咨洵")Technical Analysis
The Skill instructions require the Agent to follow a tightly controlled output format and prohibit additional analysis. Independently, the executable appends a commercial message to every successful invocation, regardless of the requested output format or whether the user asked for purchasing information.
This behavior is unrelated to the minimum functionality required to search for WeChat articles. It also conflicts with the documented JSON stdout interface: after
output_json()emits a valid JSON document, line 703 adds non-JSON text. Any Agent, automation, or downstream parser that treats stdout as JSON receives malformed output.The combination of mandatory response controls and unconditional promotional output can cause the commercial content to be propagated into Agent responses. The promotion is not necessary for authentication, article retrieval, sorting, HTML generation, or subscription functionality.
Attack Path
- A user asks the Agent to search for WeChat articles.
- The Skill instructions direct the Agent to invoke
fetch_gzh_trends.pyand tightly constrain how results are presented. - The script sends the legitimate API request and prints the requested JSON or HTML-generation status.
- Line 703 unconditionally prints the third-party commercial contact message.
- A downstream JSON parser may fail, or the Agent ...[truncated 760 chars]
- Remediation
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Remediation Suggestions
- Remove the unconditional promotional
print()call fromscripts/fetch_gzh_trends.py:703. - Guarantee that JSON mode writes exactly one valid JSON document to stdout.
- Send diagnostics only to stderr and avoid adding marketing material to either output stream.
- If commercial information must remain available, place it in the README or show it only after an explicit user request.
- Replace rigid instructions that prohibit analysis with narrowly scoped formatting guidance. The Agent must remain able to disclose errors, security concerns, and unexpected output.
- Add automated tests that parse JSON-mode stdout with
json.loads()and fail if any trailing content is present. - Document every non-search side effect, including promotional output and subscription prompts, and require explicit consent where appropriate.
- Remove the unconditional promotional