Broken Authentication

Broken Authentication in Go (Gin) [Jun 2026] [CVE-2026-38567]

[Updated Jun 2026] Updated CVE-2026-38567

Overview

The CVE-2026-38567 entry describes a SQL injection flaw in HireFlow v1.2 affecting the /login and /search endpoints. An unauthenticated attacker could bypass authentication by crafting a username such as admin'-- or exfiltrate the entire database using UNION-based injections at /search. This vulnerability enables credential theft and broad data exposure. In real-world Go (Gin) deployments, such issues emerge when user input is concatenated into SQL strings rather than bound as parameters, enabling attackers to alter query logic. In Go with Gin, this manifests when endpoints build SQL statements by concatenating user-supplied values (username, password, or search terms) directly into the query text. Without parameter binding, an attacker can terminate strings and inject malicious SQL, leading to login bypass or data leakage. The remediation is to replace string concatenation with parameterized queries (prepared statements or queries with placeholders), and to adopt least-privilege DB access, input validation, and proper error handling. The code example below demonstrates vulnerable versus fixed patterns in the same Gin app, mapped to the CVE context. Remediation focuses on binding inputs instead of embedding them, using placeholders like ? (works with MySQL/SQLite) or $1 style for PostgreSQL, and applying context timeouts where appropriate. After applying the fix, the login flow cannot be manipulated via crafted usernames, and search results can no longer reveal arbitrary data through injection.

Affected Versions

HireFlow v1.2

Code Fix Example

Go (Gin) API Security Remediation
package main

import (
  "database/sql"
  "log"
  "net/http"

  "github.com/gin-gonic/gin"
  _ "github.com/mattn/go-sqlite3"
)

func main() {
  db, err := sql.Open("sqlite3", ":memory:")
  if err != nil {
    log.Fatal(err)
  }
  defer db.Close()

  // Initialize schema and seed data (for demonstration)
  if _, err := db.Exec("CREATE TABLE users (id INTEGER PRIMARY KEY AUTOINCREMENT, username TEXT, password TEXT)"); err != nil {
    log.Fatal(err)
  }
  if _, err := db.Exec("INSERT INTO users (username, password) VALUES ('admin','secret'), ('alice','password')"); err != nil {
    log.Fatal(err)
  }

  r := gin.Default()

  // Vulnerable endpoints: string concatenation allowing SQL injection
  r.POST("/login", func(c *gin.Context) {
    username := c.PostForm("username")
    password := c.PostForm("password")
    // Vulnerable: concatenates user input directly into SQL
    query := "SELECT id FROM users WHERE username = '" + username + "' AND password = '" + password + "'"
    row := db.QueryRow(query)
    var id int
    if err := row.Scan(&id); err == nil {
      c.JSON(http.StatusOK, gin.H{"status": "authenticated", "id": id})
    } else {
      c.JSON(http.StatusUnauthorized, gin.H{"status": "unauthorized"})
    }
  })

  r.GET("/search", func(c *gin.Context) {
    q := c.Query("q")
    // Vulnerable: concatenates input into LIKE clause
    query := "SELECT id, username FROM users WHERE username LIKE '" + q + "%'"
    rows, err := db.Query(query)
    if err != nil {
      c.JSON(http.StatusInternalServerError, gin.H{"error": "query"})
      return
    }
    defer rows.Close()
    var results []gin.H
    for rows.Next() {
      var id int
      var uname string
      if err := rows.Scan(&id, &uname); err == nil {
        results = append(results, gin.H{"id": id, "username": uname})
      }
    }
    c.JSON(http.StatusOK, results)
  })

  // Fixed endpoints: parameterized queries
  r.POST("/login-fixed", func(c *gin.Context) {
    username := c.PostForm("username")
    password := c.PostForm("password")
    // Fixed: parameterized query using placeholders
    query := "SELECT id FROM users WHERE username = ? AND password = ?"
    row := db.QueryRow(query, username, password)
    var id int
    if err := row.Scan(&id); err == nil {
      c.JSON(http.StatusOK, gin.H{"status": "authenticated", "id": id})
    } else {
      c.JSON(http.StatusUnauthorized, gin.H{"status": "unauthorized"})
    }
  })

  r.GET("/search-fixed", func(c *gin.Context) {
    q := c.Query("q")
    // Fixed: parameterized LIKE using placeholder
    query := "SELECT id, username FROM users WHERE username LIKE ?"
    rows, err := db.Query(query, q+"%")
    if err != nil {
      c.JSON(http.StatusInternalServerError, gin.H{"error": "query"})
      return
    }
    defer rows.Close()
    var results []gin.H
    for rows.Next() {
      var id int
      var uname string
      if err := rows.Scan(&id, &uname); err == nil {
        results = append(results, gin.H{"id": id, "username": uname})
      }
    }
    c.JSON(http.StatusOK, results)
  })

  r.Run(":8080")
}

CVE References

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