Skip to main content

Security controls bypass or absence - Antivirus

Need​

Implementation of robust security controls and regular updates for antivirus software

Context​

  • Usage of Go 1.16 for building efficient and scalable applications
  • Usage of Gin framework for building web applications in Go
  • Usage of net/http for building HTTP servers in a Node.js application
  • Usage of the os module for operating system related functionalities

Description​

Non compliant code​

package main

import (
	"github.com/gin-gonic/gin"
	"net/http"
	"os"
)

func main() {
	r := gin.Default()

	r.GET("/disable-antivirus", func(c *gin.Context) {
		_, err := os.Create("/path/to/antivirus/disable")
		if err != nil {
			c.JSON(http.StatusInternalServerError, gin.H{"status": "unable to disable antivirus"})
			return
		}
		c.JSON(http.StatusOK, gin.H{"status": "antivirus disabled"})
	})

	r.Run() // Listen and serve on 0.0.0.0:8080
}

The above code is a simple Go server application using the Gin framework. It has a single endpoint, /disable-antivirus, that when accessed with a GET request, it creates a file at the path /path/to/antivirus/disable.

The creation of this file is intended to represent a mechanism for disabling the antivirus software. This is a serious security vulnerability as it allows any client to disable the antivirus protection simply by sending a GET request to the /disable-antivirus endpoint.

This vulnerability could be exploited by an attacker to disable the antivirus software and then carry out malicious activities without being detected. The absence of antivirus protection could lead to various attacks such as virus infection, data theft, or even system takeover.

The vulnerability lies in the fact that the application does not implement any security controls to prevent unauthorized access to the /disable-antivirus endpoint. Therefore, any client, regardless of their privileges, can send a GET request to this endpoint and disable the antivirus software.

Steps​

  • Implement proper access controls to restrict unauthorized access to the endpoint that disables antivirus.
  • Ensure that only authorized users or roles can access the endpoint.
  • Consider implementing authentication and authorization mechanisms to validate the identity and permissions of the users.
  • Implement input validation to prevent any malicious input that can be used to bypass security controls.
  • Regularly update and patch the antivirus software to ensure it has the latest security features and protections.
  • Monitor and log any attempts to disable antivirus or modify antivirus-related files.
  • Implement intrusion detection and prevention systems to detect and block any suspicious activities.
  • Perform regular security assessments and penetration testing to identify and fix any vulnerabilities in the application.
  • Educate developers and users about the importance of antivirus protection and the risks associated with disabling it.

Compliant code​

package main

import (
	"github.com/gin-gonic/gin"
	"net/http"
	"os"
	"errors"
)

func main() {
	r := gin.Default()

	r.Use(AuthMiddleware()) // Add authentication middleware

	r.GET("/disable-antivirus", func(c *gin.Context) {
		user, _ := c.Get("user")
		if !user.(User).IsAdmin { // Check if user has admin role
			c.JSON(http.StatusForbidden, gin.H{"status": "access denied"})
			return
		}

		_, err := os.Create("/path/to/antivirus/disable")
		if err != nil {
			c.JSON(http.StatusInternalServerError, gin.H{"status": "unable to disable antivirus"})
			return
		}
		c.JSON(http.StatusOK, gin.H{"status": "antivirus disabled"})
	})

	r.Run() // Listen and serve on 0.0.0.0:8080
}

type User struct {
	IsAdmin bool
}

func AuthMiddleware() gin.HandlerFunc {
	return func(c *gin.Context) {
		// Implement your authentication logic here
		// For example, you can get user info from JWT token and set it to context
		user := User{IsAdmin: true} // This is just an example, replace it with your real authentication logic
		c.Set("user", user)
		c.Next()
	}
}

The original code had a vulnerability where any user could access the endpoint to disable the antivirus. This is a serious security risk as it could allow an attacker to disable the antivirus and perform malicious activities.

The fixed code introduces an authentication middleware that validates the user's identity before they can access any endpoint. This middleware can be used to implement any authentication mechanism, such as JWT, OAuth, etc.

In the /disable-antivirus endpoint, we added a check to ensure that only users with the admin role can disable the antivirus. If a non-admin user tries to access this endpoint, they will receive a "access denied" response.

This fix significantly reduces the risk of an attacker being able to disable the antivirus, as they would need to have valid admin credentials to do so. However, it's important to note that this is just one layer of defense and other security measures should also be implemented, such as input validation, regular updates and patches, intrusion detection and prevention systems, and regular security assessments.

References​

Last updated on