Impact Analysis

This vulnerability can lead to unauthorized disclosure and duplication of sensitive tenant data, including documents, FAQ content, and configuration details.

• An attacker with low privileges but authenticated access can exfiltrate bulk data from other tenants.
• Confidentiality of tenant data is severely compromised, though integrity and availability are not affected.
• It can result in data breaches and loss of trust between tenants sharing the platform.

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Compliance Impact

I don't know

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Executive Summary

[{'type': 'paragraph', 'content': 'CVE-2026-30857 is a Broken Access Control vulnerability in the Tencent WeKnora knowledge base system affecting versions prior to 0.3.0. It occurs in the knowledge base copy endpoint, where any authenticated user can clone another tenant’s knowledge base by providing the source knowledge base ID without proper authorization checks.'}, {'type': 'paragraph', 'content': "The vulnerability arises because the system does not verify if the source knowledge base belongs to the requesting user's tenant. The cloning process copies all data and configurations from the victim’s knowledge base into the attacker’s tenant, enabling unauthorized access and duplication of sensitive information."}] [1]

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Detection Guidance

[{'type': 'paragraph', 'content': "This vulnerability can be detected by monitoring for unauthorized POST requests to the /api/v1/knowledge-bases/copy endpoint that include source knowledge base IDs (source_id) not belonging to the authenticated user's tenant."}, {'type': 'paragraph', 'content': 'Specifically, detection involves checking logs or network traffic for POST requests where an authenticated user attempts to clone knowledge bases from other tenants by supplying source_id values that do not match their tenant.'}, {'type': 'paragraph', 'content': 'Suggested commands to detect such activity might include searching server logs or API gateway logs for suspicious POST requests. For example, using grep on server logs:'}, {'type': 'list_item', 'content': "grep 'POST /api/v1/knowledge-bases/copy' /path/to/access.log | grep 'source_id='"}, {'type': 'paragraph', 'content': 'Additionally, monitoring for unusual cloning activity or spikes in knowledge base duplication requests by authenticated users can help identify exploitation attempts.'}] [1]

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Mitigation Strategies

The immediate mitigation step is to upgrade the Tencent WeKnora system to version 0.3.0 or later, where this vulnerability has been patched.

Until the upgrade can be performed, restrict access to the /api/v1/knowledge-bases/copy endpoint to only trusted users or disable it if possible.

Implement additional monitoring and alerting for suspicious cloning requests that may indicate exploitation attempts.

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