MySQL MCP Server: Missing Origin/Host Validation in SSE Transport Enables Unauthenticated SQL Execution (DNS Rebinding / Direct Exposure)
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 0.4.2
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
The MySQL MCP Server, a Model Context Protocol server for MySQL databases, is affected when it is run with its SSE transport, which is exposed on the network by default and lacks origin, host, or authentication checks. An attacker who can reach the service, or who lures a user's browser into relaying requests to a locally running instance, could run arbitrary SQL against the configured database, allowing unauthorized reading and modification of data (and, if the database account has FILE privileges, possibly server files as well).
Summarized by anthropic/claude-haiku-5.5. Verify details against the original sources.
Read the original description
MySQL MCP Server is a Model Context Protocol server that enables secure interaction with MySQL databases. Prior to 0.4.2, setting MCP_TRANSPORT=sse causes src/mysql_mcp_server/server.py to construct SseServerTransport without security_settings or enable_dns_rebinding_protection, while the Starlette routes /, /sse, and /messages/ have no authentication and the service binds to 0.0.0.0 by default. A network attacker can directly reach execute_sql, or can use DNS rebinding to make a victim's browser relay same-origin requests to a locally bound service, and supply a query that reaches cursor.execute(query). This allows unauthenticated disclosure and modification of the configured database; when the MySQL account has FILE privileges, the same access can read or write server files and may enable code execution. The default stdio transport is not affected. This issue is fixed in 0.4.2.
Timeline
- CVE published
- Record last updated
Affected versions
- designcomputer mysql_mcp_server
fixed in 0.4.2
- mysql-mcp-serverPyPI
fixed in 0.4.2