Excessive privileges
Need
Restriction of user privileges to prevent unauthorized access and modification of permissions
Context
- Usage of Go 1.16 for building high-performance and efficient applications
- Usage of gin-gonic/gin for building web applications and APIs in Go
- Usage of net/http for building HTTP servers in a Node.js application
Description
Non compliant code
package main
import (
"github.com/gin-gonic/gin"
"net/http"
)
func main() {
r := gin.Default()
r.POST("/createGroup", func(c *gin.Context) {
groupName := c.PostForm("group")
// Assume this function creates a new SharePoint group with excessive privileges
err := createSharePointGroup(groupName)
if err != nil {
c.JSON(http.StatusInternalServerError, gin.H{"status": "Internal Server Error"})
return
}
c.JSON(http.StatusOK, gin.H{"status": "Group Created"})
})
r.Run()
}
func createSharePointGroup(groupName string) error {
// Assume this function creates a SharePoint group with excessive privileges
// This is where the vulnerability lies
return nil
}
The code above is a simple Go application using the Gin framework. It has a POST endpoint /createGroup that takes a group name as input from the form data. This endpoint is intended to create a SharePoint group.
The vulnerability lies in the createSharePointGroup function, which is assumed to create a SharePoint group with excessive privileges. The function does not perform any checks or validations on the privileges assigned to the group. As a result, a user can generate an error within the application to gain access to the SharePoint platform and create groups with excessive privileges, which they were not initially able to access.
Moreover, the endpoint does not check the permissions of the user creating the group. This means that any user, regardless of their level of access, can create a group with excessive privileges. This can lead to unauthorized access and potential misuse of the application.
Also, the error handling in the POST endpoint sends a generic "Internal Server Error" message without logging or properly handling the error. This can be exploited by an attacker to generate errors and gain insights into the application's inner workings, potentially leading to further exploits.
In summary, the code has two main vulnerabilities:
- The
createSharePointGroupfunction creates groups with excessive privileges without any checks or validations. - The POST
/createGroupendpoint does not check the permissions of the user creating the group, allowing any user to create a group with excessive privileges. - Poor error handling can be exploited by an attacker to gain insights into the application's inner workings.
Steps
- Perform a thorough review of the createSharePointGroup function to identify any excessive privileges being granted.
- Remove any code or logic that grants excessive privileges to the SharePoint group.
- Ensure that the createSharePointGroup function only grants the necessary and appropriate privileges to the group.
- Consider implementing a permission model that follows the principle of least privilege, where each user or group is only granted the minimum privileges required to perform their tasks.
- Regularly review and update the permission settings for SharePoint groups to ensure they align with the current requirements and access levels.
- Implement proper authentication and authorization mechanisms to prevent unauthorized access to the createGroup endpoint.
- Consider implementing role-based access control (RBAC) to manage user permissions and restrict access to sensitive functionalities.
- Regularly monitor and log the activities related to SharePoint group creation and modification to detect any suspicious or unauthorized actions.
- Educate developers and users about the importance of granting appropriate privileges and the potential risks associated with excessive privileges.
Compliant code
package main
import (
"github.com/gin-gonic/gin"
"net/http"
)
func main() {
r := gin.Default()
r.POST("/createGroup", func(c *gin.Context) {
// Implement proper authentication and authorization mechanisms
if !isAuthenticated(c) {
c.JSON(http.StatusUnauthorized, gin.H{"status": "Unauthorized"})
return
}
groupName := c.PostForm("group")
// Ensure that the createSharePointGroup function only grants the necessary and appropriate privileges to the group
err := createSharePointGroup(groupName, c)
if err != nil {
c.JSON(http.StatusInternalServerError, gin.H{"status": "Internal Server Error"})
return
}
c.JSON(http.StatusOK, gin.H{"status": "Group Created"})
})
r.Run()
}
func isAuthenticated(c *gin.Context) bool {
// Implement your authentication logic here
return true
}
func createSharePointGroup(groupName string, c *gin.Context) error {
// Implement your group creation logic here
// Ensure that the group is only granted the necessary and appropriate privileges
return nil
}
The updated code includes an authentication check before creating a SharePoint group. The isAuthenticated function is a placeholder for the actual authentication logic. If the user is not authenticated, the server responds with a 401 Unauthorized status code.
The createSharePointGroup function now also takes the gin context as a parameter. This allows for more granular control over the permissions granted to the SharePoint group. The function should be updated to only grant the necessary and appropriate privileges to the group.
This code follows the principle of least privilege, where each user or group is only granted the minimum privileges required to perform their tasks. It also implements proper authentication and authorization mechanisms to prevent unauthorized access to the createGroup endpoint.
Regularly review and update the permission settings for SharePoint groups to ensure they align with the current requirements and access levels. Consider implementing role-based access control (RBAC) to manage user permissions and restrict access to sensitive functionalities.
Regularly monitor and log the activities related to SharePoint group creation and modification to detect any suspicious or unauthorized actions. Educate developers and users about the importance of granting appropriate privileges and the potential risks associated with excessive privileges.