Overview
CVE-2026-34570 describes a broken session revocation scenario in a CodeIgniter 4-based CMS (CI4MS) where deleting an account does not immediately revoke active sessions; authentication-only checks allow previously authenticated users to retain access until they log out. This is tied to CWE-284 (Improper Access Control) and CWE-613 (Insufficient Session Expiration), with CWE-1254 also noted. The patch in CI4MS landed in version 0.31.0.0. In Go (Gin) contexts, this vulnerability maps to Broken Object Level Authorization (BOLA): an API may authenticate a user but fail to enforce per-request, object-level ownership or account status, allowing a user to access resources owned by others or continue access after their own account is deactivated if the session/token is not revoked. The real-world impact is persistent, cross-user access and privilege abuse, even after account changes, which aligns with the described CVE’s lessons about failing to revoke access promptly. This guide references CVE-2026-34570 as the inspiration for per-request authorization failures and token/session revocation gaps and demonstrates a Go Gin remediation pattern with explicit ownership checks and revocation semantics.
Code Fix Example
Go (Gin) API Security Remediation
package main
import (
"net/http"
"strconv"
"time"
"github.com/gin-gonic/gin"
)
type User struct {
ID int
Name string
Active bool
Role string
TokenVersion int
}
type Resource struct {
ID int
OwnerID int
Data string
}
var users = map[int]User{
1: {ID: 1, Name: "Alice", Active: true, Role: "user", TokenVersion: 1},
2: {ID: 2, Name: "Bob", Active: true, Role: "user", TokenVersion: 1},
3: {ID: 3, Name: "Admin", Active: true, Role: "admin", TokenVersion: 1},
}
var resources = map[int]Resource{
10: {ID: 10, OwnerID: 1, Data: "Alice's secret"},
20: {ID: 20, OwnerID: 2, Data: "Bob's secret"},
}
// Simple in-memory token store for demonstration; replace with JWTs in real apps
type Token struct { UserID int; TokenVersion int; Expires time.Time }
var tokens = map[string]Token{
"token-1-1": {UserID: 1, TokenVersion: 1, Expires: time.Now().Add(24 * time.Hour)},
"token-2-1": {UserID: 2, TokenVersion: 1, Expires: time.Now().Add(24 * time.Hour)},
"token-admin-1": {UserID: 3, TokenVersion: 1, Expires: time.Now().Add(24 * time.Hour)},
}
func main() {
r := gin.Default()
// Vulnerable pattern (no object-level check on ownership)
r.GET("/vulnerable/resources/:id", vulnerableResource)
// Fix: enforce object-level authorization and account/token checks
r.GET("/secure/resources/:id", secureResource)
// Admin endpoint to simulate account deactivation and token revocation
r.POST("/admin/deactivate/:id", deactivateUser)
r.Run(":8080")
}
func authenticate(c *gin.Context) (User, bool) {
auth := c.GetHeader("Authorization")
if len(auth) < 7 || auth[:7] != "Bearer " {
c.AbortWithStatus(http.StatusUnauthorized)
return User{}, false
}
token := auth[7:]
t, ok := tokens[token]
if !ok || time.Now().After(t.Expires) {
c.AbortWithStatus(http.StatusUnauthorized)
return User{}, false
}
u, ok := users[t.UserID]
if !ok {
c.AbortWithStatus(http.StatusUnauthorized)
return User{}, false
}
c.Set("user", u)
c.Set("tokenVersion", t.TokenVersion)
return u, true
}
func vulnerableResource(c *gin.Context) {
u, ok := authenticate(c)
if !ok {
return
}
id, _ := strconv.Atoi(c.Param("id"))
res, exists := resources[id]
if !exists {
c.JSON(http.StatusNotFound, gin.H{"error": "not found"})
return
}
// Vulnerable: any authenticated user can access any resource regardless of ownership
c.JSON(http.StatusOK, gin.H{"owner": res.OwnerID, "data": res.Data, "requestedBy": u.ID})
}
func secureResource(c *gin.Context) {
u, ok := authenticate(c)
if !ok {
return
}
if !u.Active {
c.JSON(http.StatusUnauthorized, gin.H{"error": "account inactive"})
return
}
tv, _ := c.Get("tokenVersion")
if u.TokenVersion != tv.(int) {
c.JSON(http.StatusUnauthorized, gin.H{"error": "token revoked"})
return
}
id, _ := strconv.Atoi(c.Param("id"))
res, exists := resources[id]
if !exists {
c.JSON(http.StatusNotFound, gin.H{"error": "not found"})
return
}
// Enforce object-level access: only owner or admin can read
if res.OwnerID != u.ID && u.Role != "admin" {
c.JSON(http.StatusForbidden, gin.H{"error": "forbidden"})
return
}
c.JSON(http.StatusOK, gin.H{"owner": res.OwnerID, "data": res.Data})
}
func deactivateUser(c *gin.Context) {
admin, ok := authenticate(c)
if !ok {
return
}
if admin.Role != "admin" {
c.JSON(http.StatusForbidden, gin.H{"error": "admin privileges required"})
return
}
id, _ := strconv.Atoi(c.Param("id"))
user, exists := users[id]
if !exists {
c.JSON(http.StatusNotFound, gin.H{"error": "user not found"})
return
}
user.Active = false
user.TokenVersion += 1 // invalidate existing tokens
users[id] = user
c.JSON(http.StatusOK, gin.H{"status": "user deactivated", "userId": id})
}