WeKnora is an LLM-powered framework designed for deep document understanding and semantic retrieval. Prior to version 0.2.12, a remote code execution (RCE) vulnerability exists in the application's database query functionality. The validation system fails to recursively inspect child nodes within PostgreSQL array expressions and row expressions, allowing attackers to bypass SQL injection protections. By smuggling dangerous PostgreSQL functions inside these expressions and chaining them with large object operations and library loading capabilities, an unauthenticated attacker can achieve arbitrary code execution on the database server with database user privileges. This issue has been patched in version 0.2.12.

Affected: Go: github.com/Tencent/WeKnora

## Summary

A critical Remote Code Execution (RCE) vulnerability exists in the application's database query functionality. The validation system fails to recursively inspect child nodes within PostgreSQL array expressions and row expressions, allowing attackers to bypass SQL injection protections. By smuggling dangerous PostgreSQL functions inside these expressions and chaining them with large object operations and library loading capabilities, an unauthenticated attacker can achieve arbitrary code execution on the database server with database user privileges.

**Impact:** Complete system compromise with arbitrary code execution ---

## Details

### Root Cause Analysis

The application implements a 7-phase SQL validation framework in `internal/utils/inject.go` designed to prevent SQL injection attacks:

| Phase | Validation Type | Status | |-------|-----------------|--------| | Phase 1 | Null byte and length checks | ✅ Working | | Phase 2 | PostgreSQL AST parsing via `pg_query_go/v6` | ✅ Working | | Phase 3 | Single statement enforcement | ✅ Working | | Phase 4 | SELECT-only queries | ✅ Working | | Phase 5 | Deep SELECT statement validation | ❌ **Incomplete** | | Phase 6 | Table whitelist validation | ✅ Working | | Phase 7 | Regex-based keyword detection | ✅ Working |

### Critical Vulnerability: Incomplete AST Node Validation

The `validateNode()` function in Phase 5 fails to handle two critical PostgreSQL expression types: `ArrayExpr` (array expressions) and `RowExpr` (…