Overview
CVE-2026-29197 describes a broken object-level authorization scenario affecting multiple Go (Gin) deployments. In these versions, the endpoints /api/apps/logs and /api/apps/:id/logs carried a typo in the required permission check, which could allow authenticated users without the proper per-app authorization to read apps-engine logs. This kind of vulnerability results in unintended data exposure, leaking sensitive operational logs that may contain configuration details, secrets, or user activity. The issue is categorized under CWE-284: Improper Access Control, because access decisions are not correctly enforced for specific resources (in this case, per-app logs). The real-world risk includes leakage of logs across all apps the user should not be able to inspect, enabling reconnaissance, privacy violations, and potential exploitation of debugging data. In Go with Gin, permission checks are commonly implemented as explicit checks in handlers or via middleware; when a typo or mis-scoped check occurs, per-resource access control can be bypassed for authenticated users with broad but inappropriate access. This guide uses the CVEs above to illustrate how such a typo manifests in code and how to fix it with per-app authorization in Gin-based apps. CWE-284 requires validating permissions for each individual resource before returning its data, which is precisely what was missed in the affected versions of the referenced project.
Affected Versions
In versions <8.4.0, <8.3.2, <8.2.2, <8.1.3, <8.0.4, <7.13.6, <7.12.7, <7.11.7, and <7.10.10
Code Fix Example
Go (Gin) API Security Remediation
package main
import (
"net/http"
"github.com/gin-gonic/gin"
)
type User struct {
ID string
Roles []string
}
type App struct {
ID string
OwnerID string
}
// In-memory demo data
var apps = map[string]App{
"1": {ID: "1", OwnerID: "alice"},
}
func main() {
r := gin.Default()
// Vulnerable endpoint (for reference)
r.GET("/api/apps/:id/logs", vulnerableGetAppLogs)
// Fixed endpoint with proper per-app authorization
r.GET("/api/apps/:id/logs/fixed", fixedGetAppLogs)
r.Run()
}
func getCurrentUser(c *gin.Context) *User {
// In real apps, extract user from JWT/session. Here we simulate.
return &User{ID: "bob", Roles: []string{"user"}}
}
func getAppByID(id string) (App, bool) {
a, ok := apps[id]
return a, ok
}
// Vulnerable: typo/mis-scope in permission check
func vulnerableGetAppLogs(c *gin.Context) {
user := getCurrentUser(c)
appID := c.Param("id")
if appID == "" {
c.AbortWithStatus(http.StatusBadRequest)
return
}
app, ok := getAppByID(appID)
if !ok {
c.AbortWithStatus(http.StatusNotFound)
return
}
// Typo in permission logic: uses a global-ish check instead of per-app authorization
// This function incorrectly grants access to non-admin users regardless of app ownership
if !hasGlobalReadAccess(user) {
c.AbortWithStatus(http.StatusForbidden)
return
}
// Return demo logs
c.JSON(http.StatusOK, gin.H{"logs": []string{"log1", "log2"}})
_ = app
}
// Fixed: per-app authorization based on resource ownership/roles
func fixedGetAppLogs(c *gin.Context) {
user := getCurrentUser(c)
appID := c.Param("id")
if appID == "" {
c.AbortWithStatus(http.StatusBadRequest)
return
}
app, ok := getAppByID(appID)
if !ok {
c.AbortWithStatus(http.StatusNotFound)
return
}
if !hasPerAppReadAccess(user, app) {
c.AbortWithStatus(http.StatusForbidden)
return
}
c.JSON(http.StatusOK, gin.H{"logs": []string{"log1", "log2"}})
}
// Vulnerable helper (illustrative) - returns true for most authenticated users (bug)
func hasGlobalReadAccess(u *User) bool {
if u == nil {
return false
}
// Buggy: this grants access broadly based on user presence, not per-app
return true
}
// Fixed helper: proper per-app authorization
func hasPerAppReadAccess(u *User, a App) bool {
if u == nil {
return false
}
// Admins can read any app logs
for _, r := range u.Roles {
if r == "admin" {
return true
}
}
// Per-app ownership check
return a.OwnerID == u.ID
}