Attack Chain

1. Attacker identifies a BidingCC BuildingAI instance running a vulnerable version (<= 26.0.1).
2. Attacker crafts a malicious URL containing the address of an internal resource or external server.
3. Attacker calls the uploadRemoteFile API endpoint, providing the crafted URL as the url argument.
4. The uploadRemoteFile function, without proper validation, uses the provided URL to initiate a request.
5. The BuildingAI server makes an HTTP request to the attacker-specified URL.
6. If the URL points to an internal resource, the server retrieves sensitive data from that resource.
7. If the URL points to an external server controlled by the attacker, the server may leak internal information (e.g., internal IP addresses) or be used for further attacks.
8. The attacker receives the response from the manipulated request, achieving information disclosure or a foothold for further exploitation.

Impact

Successful exploitation of the SSRF vulnerability (CVE-2026-7065) in BidingCC BuildingAI can lead to the exposure of sensitive internal information, such as configuration files, internal service endpoints, and potentially database credentials. This information can be leveraged to further compromise the BuildingAI instance or other internal systems. The impact is significant due to the potential for lateral movement and privilege escalation within the affected organization’s infrastructure. The lack of vendor response exacerbates the risk.

Recommendation

• Deploy the Sigma rule provided below to detect exploitation attempts against the uploadRemoteFile endpoint (Log source: webserver).
• Implement strict input validation and sanitization on the url parameter of the uploadRemoteFile function to prevent arbitrary URL requests (CVE-2026-7065).
• Consider restricting outbound network access from the BuildingAI server to only necessary resources to limit the impact of successful SSRF attacks.
• Monitor web server logs for unusual requests originating from the BuildingAI server to detect potential SSRF activity.