Attack Chain

1. The attacker identifies a vulnerable instance of eiceblue spire-pdf-mcp-server 0.1.1 exposed to the network.
2. The attacker crafts a malicious HTTP request targeting the get_pdf_path function, embedding a path traversal sequence (e.g., ../) within the filepath parameter.
3. The server receives the request and processes the filepath argument without proper sanitization or validation.
4. The get_pdf_path function constructs a file path using the attacker-controlled input, allowing the traversal of directories outside the intended PDF file storage location.
5. The server attempts to access a file outside the intended directory, based on the manipulated path.
6. If successful, the server reads the contents of the arbitrary file.
7. The server returns the contents of the file to the attacker.
8. The attacker gains unauthorized access to sensitive information, potentially including configuration files, credentials, or other confidential data.

Impact

Successful exploitation of CVE-2026-7315 allows a remote attacker to read arbitrary files on the server. This can lead to the disclosure of sensitive information, such as configuration files, credentials, or internal application code. The impact could include complete compromise of the affected system and potential lateral movement within the network. Given the availability of public exploits, the risk of widespread exploitation is elevated.

Recommendation

• Deploy the Sigma rule Detect Spire-PDF Path Traversal Attempt to identify malicious requests containing path traversal sequences.
• Monitor web server logs for HTTP requests targeting the get_pdf_path function with suspicious filepath parameters (e.g., containing “../”).
• Implement strict input validation and sanitization measures for the filepath argument in the get_pdf_path function to prevent path traversal attacks.
• Apply any available patches or updates from the vendor as soon as they are released to address CVE-2026-7315.