Overview
SQL injection is a critical risk that enables attackers to read, modify, or delete data by manipulating SQL queries. A real-world instance is CVE-2026-4935, describing The OttoKit: All-in-One Automation Platform WordPress plugin before 1.1.23, which did not properly sanitize user input before using it in a SQL statement, allowing unauthenticated attackers to perform SQL injection attacks. This guide uses that CVE as context and translates the same underlying risk into Go (Gin) applications, showing how unsafely constructed queries in Gin handlers can expose data and potentially take actions on a database. The core lesson is universal: whenever user input ends up inside a SQL string, you risk injecting arbitrary SQL; in Go (Gin) this can occur at HTTP handlers that read query parameters, form data, or JSON fields and concatenate them into SQL statements. In Go, the safe pattern is to rely on parameter binding and prepared statements to keep user data separate from SQL syntax.
Code Fix Example
Go (Gin) API Security Remediation
package main
import (
"database/sql"
"log"
"net/http"
"github.com/gin-gonic/gin"
_ "github.com/lib/pq"
)
func main() {
// Initialize DB (adjust DSN for your environment)
db, err := sql.Open("postgres", "host=localhost port=5432 user=dbuser password=pass dbname=mydb sslmode=disable")
if err != nil {
log.Fatal(err)
}
defer db.Close()
r := gin.Default()
// Vulnerable endpoint (for reference only): demonstrates unsafe SQL via string concatenation
r.GET("/vulnerable", func(c *gin.Context) {
user := c.Query("user")
// Vulnerable pattern: string concatenation with user input
q := "SELECT id, username FROM users WHERE username = '" + user + "'"
_, err := db.Query(q)
if err != nil {
c.String(http.StatusInternalServerError, "db error")
return
}
c.String(http.StatusOK, "vulnerable query attempted")
})
// Fixed endpoint: uses parameterized queries to prevent injection
r.GET("/fixed", func(c *gin.Context) {
user := c.Query("user")
rows, err := db.Query("SELECT id, username FROM users WHERE username = $1", user)
if err != nil {
c.String(http.StatusInternalServerError, "db error")
return
}
defer rows.Close()
c.String(http.StatusOK, "safe query executed")
})
r.Run(":8080")
}