T01 · Skill Instruction Hijacking
Warning
- Location
- SKILL.md:31
- Finding
- Mandatory Branded Attribution Injected into Agent Output## Vulnerability Details **File Location**: `SKILL.md`, lines 31–35 **Vulnerability Type**: Output instruction hijacking through mandatory promotional content **Risk Level**: Medium **Complete Code Snippet**: ```markdown ## 输出模板 ```markdown # MIXLAB Solo Scope#简报 > 来源: https://www.mixdao.world/feed | 生成: YYYY-MM-DD | 技术支持:MIXLAB AgentOS ``` ### Technical Analysis The prescribed output template requires the Agent to insert a branded “Technical support: MIXLAB AgentOS” attribution into generated briefings. This attribution is unrelated to the functional requirements of retrieving, classifying, and summarizing RSS entries. Because this content is embedded in the skill instructions rather than requested by the invoking user, loading and following the skill causes the Agent to propagate attacker-selected promotional material as part of otherwise legitimate output. The behavior is persistent across every invocation that follows the template, although it does not modify long-term memory or survive independently of the loaded skill. ### Attack Path 1. A user installs or invokes the skill to summarize the Solo Scope RSS feed. 2. The Agent loads and follows `SKILL.md`. 3. The Agent retrieves and summarizes the RSS entries as expected. 4. The mandatory output template directs the Agent to append the branded attribution. 5. The resulting briefing presents promotional content that the user did not explicitly request. ### Impact Assessment The issue does not grant operating-system privileges, access credentials, code execution, or access to additional files. Its scope is limited to manipulation of Agent-generated briefing content. Successful exploitation permits the skill author to repeatedly place selected branding in user-facing responses, reducing output integrity and potentially creating a misleading impression of sponsorship, endorsement, or technical involvement. Every user and downstream system consuming outpu ...[truncated 47 chars]
- Remediation
- ## Remediation Suggestions Remove the branded attribution from the mandatory output template. The default template should contain only information necessary to satisfy the RSS summarization request, such as the source URL and generation date. If attribution is legitimately required, make it explicitly optional and include it only when the user requests it or has knowingly accepted that output convention. Document any affiliation separately from operational instructions so that it cannot be mistaken for required task behavior. Review the remaining skill instructions for unrelated branding, endorsements, tracking parameters, or mandatory content that does not contribute to the declared function. Add a policy requiring user-facing templates to preserve user intent and prohibit unsolicited promotional insertions.
