Impact
MySQLSelectTool is intended to be a read-only SQL tool (e.g., for LLM agent querying). However, validation based on the first keyword (e.g., SELECT) and a forbidden-keyword list does not block file-writing constructs such as INTO OUTFILE / INTO DUMPFILE.
As a result, an attacker who can influence the tool input (e.g., prompt injection through a public agent endpoint) may be able to write arbitrary content to files on the DB server.
If the MySQL/MariaDB account has the FILE privilege and server configuration permits writes to a useful location (e.g., a web-accessible directory), the impact can escalate to remote code execution on the application host (for example, by writing a PHP web shell).
Who is impacted: Deployments that expose an agent using MySQLSelectTool to untrusted input and run with overly-permissive DB privileges/configuration.
Patches
Not patched in: 2.8.11
Fixed in: 2.8.12
Recommended fix direction:
-
Explicitly reject queries containing: INTO, OUTFILE, DUMPFILE, LOAD_FILE, and other file/IO-related functions/clauses.
-
Prefer AST-based validation (SQL parser) over keyword checks.
-
Constrain allowed tables/columns and disallow multi-statements.
Workarounds
If you cannot upgrade immediately:
-
Remove/disable MySQLSelectTool for any agent reachable from untrusted input.
-
Ensure DB account used by the tool does not have FILE privilege.
-
Ensure secure_file_priv is set to a directory that is not web-accessible (or restrict it tightly).
-
Add a defensive query filter at the application layer rejecting INTO OUTFILE, INTO DUMPFILE, LOAD_FILE, ; (multi-statements), and suspicious comment patterns.
References
siewer Finder
Impact
MySQLSelectToolis intended to be a read-only SQL tool (e.g., for LLM agent querying). However, validation based on the first keyword (e.g.,SELECT) and a forbidden-keyword list does not block file-writing constructs such asINTO OUTFILE/INTO DUMPFILE.As a result, an attacker who can influence the tool input (e.g., prompt injection through a public agent endpoint) may be able to write arbitrary content to files on the DB server.
If the MySQL/MariaDB account has the
FILEprivilege and server configuration permits writes to a useful location (e.g., a web-accessible directory), the impact can escalate to remote code execution on the application host (for example, by writing a PHP web shell).Who is impacted: Deployments that expose an agent using
MySQLSelectToolto untrusted input and run with overly-permissive DB privileges/configuration.Patches
Not patched in: 2.8.11
Fixed in: 2.8.12
Recommended fix direction:
Explicitly reject queries containing:
INTO,OUTFILE,DUMPFILE,LOAD_FILE, and other file/IO-related functions/clauses.Prefer AST-based validation (SQL parser) over keyword checks.
Constrain allowed tables/columns and disallow multi-statements.
Workarounds
If you cannot upgrade immediately:
Remove/disable
MySQLSelectToolfor any agent reachable from untrusted input.Ensure DB account used by the tool does not have
FILEprivilege.Ensure
secure_file_privis set to a directory that is not web-accessible (or restrict it tightly).Add a defensive query filter at the application layer rejecting
INTO OUTFILE,INTO DUMPFILE,LOAD_FILE,;(multi-statements), and suspicious comment patterns.References