Cisco RV110w UPnP stack overflow

Overview

Cisco RV110W UPnP 0day 分析

前言

最近UPnP比较火,恰好手里有一台Cisco RV110W,在2021年8月份思科官方公布了一个Cisco RV系列关于UPnP的0day,但是具体的细节并没有公布出来。于是想要用手中的设备调试挖掘一下这个漏洞,漏洞的公告可以在官网看到。

准备工作

首先将固件更新到最新版本1.2.2.8 ,接下来面临的一个问题就是如何调试和定位漏洞。首先解决调试的问题,调试的首要工作就是拿到设备的shell,不过最新的固件并没有提供调试的接口,笔者这里通过UART串口和修改固件包的方式拿到了最新固件的调试权限,具体的方法参考之前写过的一篇文章路由器调试之getshell

调试准备

Cisco RV110W是mipsel架构,所以需要先找一个对应的gdb-server,可以自己交叉编译也可以使用别人编译好的,这里推荐gdb-static-cross 。

漏洞定位

官方公告指出漏洞存在于UPnP服务中,首先进入后台管理,FireWall的Basic Settings打开UPnP的配置

Untitled

然后nmap扫一下端口,并没有发现UPnP的端口,但是测试发现UPnP的确打开了。

Untitled

这里笔者使用UPnPy进行漏洞的测试和利用。

import socket
msg = \
    b'M-SEARCH * HTTP/1.1\r\n' \
    b'HOST:239.255.255.250:1900\r\n' \
    b'ST:upnp:rootdevice\r\n' \
    b'MX:2\r\n' \
    b'MAN:"ssdp:discover"\r\n' \
    b'\r\n'

# Set up UDP socket
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP)
s.bind((b"192.168.2.100",23333)) #本机IP
s.settimeout(2)
s.sendto(msg, (b'239.255.255.250', 1900))
addr = ('192.168.2.1', 1900) # 网关IP
try:
    while True:
        data, addr = s.recvfrom(65507)
        print(addr,data)

except socket.timeout:
    pass

发现确实得到了UPnP的响应,而且在设备的进程中存在对应的UPnP进程

Untitled

服务分析

UPnP是一种通用的协议标准,厂商大多按照标准实现,即很多action都是一致的,但是也有必要对设备提供的服务进行分析以便于漏洞的定位和利用,同样使用UPnPy进行信息的收集

import upnpy
import socket

import requests
from upnpy.ssdp.SSDPDevice import SSDPDevice
msg = \
    b'M-SEARCH * HTTP/1.1\r\n' \
    b'HOST:239.255.255.250:1900\r\n' \
    b'ST:upnp:rootdevice\r\n' \
    b'MX:2\r\n' \
    b'MAN:"ssdp:discover"\r\n' \
    b'\r\n'

# Set up UDP socket
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP)
s.bind((b"192.168.2.100",23333))
s.settimeout(2)
s.sendto(msg, (b'239.255.255.250', 1900))
addr = ('192.168.2.1', 1900)
data = b""
try:
    while True:
        data, addr = s.recvfrom(65507)
        print(addr,data)
except socket.timeout:
    pass

# data = b'HTTP/1.1 200 OK\r\nCache-Control: max-age=120\r\nDate: Fri, 01 Jan 2010 00:44:16 GMT\r\nExt: \r\nLocation: http://192.168.2.1:1780/InternetGatewayDevice.xml\r\nServer: POSIX UPnP/1.0 linux/5.70.48.16\r\nST: upnp:rootdevice\r\nUSN: uuid:31474a87-67ea-dae4-2f73-f157fb06d22b::upnp:rootdevice\r\n\r\n'
# data = b'HTTP/1.1 200 OK\r\nCache-Control: max-age=3600\r\nST: upnp:rootdevice\r\nUSN: uuid:824ff22b-8c7d-41c5-a131-8c3bad401726::upnp:rootdevice\r\nEXT:\r\nServer:  Unspecified, UPnP/1.0, Unspecified\r\nLocation: http://192.168.3.1:56688/rootDesc.xml\r\n\r\n'

device = SSDPDevice(addr, data.decode())
services = device.get_services()

services_id = [services[i].id.split(":")[-1] for i in range(len(services))]

for id in services_id:
    service = device[id]
    actions = service.get_actions()
    for action in actions:
        for argument in action.arguments:
            print(id,action.name,argument.name)

可以得到一系列的服务信息,部分信息如下

WANIPConn1 AddPortMapping NewRemoteHost
WANIPConn1 AddPortMapping NewExternalPort
WANIPConn1 AddPortMapping NewProtocol
WANIPConn1 AddPortMapping NewInternalPort
WANIPConn1 AddPortMapping NewInternalClient
WANIPConn1 AddPortMapping NewEnabled
WANIPConn1 AddPortMapping NewPortMappingDescription
WANIPConn1 AddPortMapping NewLeaseDuration
WANIPConn1 DeletePortMapping NewRemoteHost
WANIPConn1 DeletePortMapping NewExternalPort
WANIPConn1 DeletePortMapping NewProtocol
WANIPConn1 GetExternalIPAddress NewExternalIPAddress

这些服务大致可以分为get类和set类,以及少数的delete类服务。由于UPnP的主要目的之一是将内网设备暴露给公网设备,这就需要进行一定的配置(端口映射等),既然需要配置,那么配置的参数和信息必不可缺,而这些参数其实就是set类服务中的参数。

服务定位

由于并不是所有服务,厂商都有实现,因此需要自己逆向一下固件。首先定位到upnp_mainloop

Untitled

所有的处理逻辑都是在upnp_dispatch中实现的,跟进分析发现了存在ssdp和http的请求处理部分

Untitled

ssdp_process对应寻址时M-Search的请求,upnp_http_process 对应http请求的处理,由于正常的服务调用都是http请求,因此判断upnp_http_process可能存在漏洞,服务调用示例如下图所示

Untitled

upnp_http_process中进一步调用了upnp_http_fsm_emgine

Untitled

跟进分析,发现会执行off_45ab80处的几个函数

Untitled

这些函数包括了初始化和解析协议头的功能,最后一个函数为upnp_http_fsm_dispatch ,猜测会执行对应的服务函数。

Untitled

跟进upnp_http_fsm_dispatch ,发现确实调用了函数方法,不过是根据a1和a2执行的函数调用,无法确定具体的被调用函数,需要动态调试。

Untitled

如果是正常的ssdp寻址请求那么会调用SUB_405B34,description_process ,如果是服务相关请求,会调用soap_process ,在soap_process中根据请求头信息,调用query_process或者action_process

主要关注action_process,根据服务调用的请求头,猜测action_process中的soap_control对应服务调用

Untitled

在soap_control中仍然需要动态调试,确定具体的函数信息。

Untitled

最终经过动态调试确定sub_414C28 对应AddPortMapping action,其函数调用链为

sub_414c28->upnp_portmap_add->upnp_osl_nat_config->strcpy(stack overflow)

不过在upnp_portmap_add中检查了一下本机的wan口地址,由于笔者在测试的时候并没有配置wan口,所以直接用nvram 设置了一下wan口ip。

Untitled

栈溢出的时候需要控制程序流走到红色的方块中,因为蓝色方块的函数会访问被溢出的栈导致程序在RCE之前崩掉,因此需要控制*(a2+11)的值为0,幸运的是此处的值是可控的

Untitled

漏洞利用

由于最新固件没有telnetd,可以反弹shell然后自己上一个utelnetd,然后开启telnet

display-exploit.gif

参考反弹shell的姿势

Owner
badmonkey
badmonkey
Apache Solr SSRF(CVE-2021-27905)

Solr-SSRF Apache Solr SSRF #Use [-] Apache Solr SSRF漏洞 (CVE-2021-27905) [-] Options: -h or --help : 方法说明 -u or --url

Henry4E36 70 Nov 09, 2022
👑 Discovery Header DoD Bug-Bounty

👑 Discovery Header DoD Bug-Bounty Did you know that DoD accepts server headers? 😲 (example: apache"version" , php"version") ? In this code it is pos

KingOfTips 38 Aug 09, 2022
This tool was created in order to automate some basic OSINT tasks for penetration testing assingments.

This tool was created in order to automate some basic OSINT tasks for penetration testing assingments. The main feature that I haven't seen much anywhere is the downloadd google dork function where t

Tobias 5 May 31, 2022
macOS Initial Access Payload Generator

Mystikal macOS Initial Access Payload Generator Related Blog Post: https://posts.specterops.io/introducing-mystikal-4fbd2f7ae520 Usage: Install Xcode

Leo Pitt 206 Dec 31, 2022
KeyLogger

By-Emirhan KeyLogger Hangi Sistemlerde Çalışır? | On Which Systems Does It Work? KALİ LİNUX UBUNTU PARDUS MİNT TERMUX ARCH YÜKLEME & ÇALIŞTIRMA KOMUTL

2 Feb 24, 2022
A Tool for subdomain scan with other tools

ReconTracer A Tool for subdomain scan with other tools ReconTracer Find subdomains by using another amazing sources!. Obs: In a close future recontrac

15 Dec 18, 2021
Static Token And Credential Scanner

Static Token And Credential Scanner What is it? STACS is a YARA powered static credential scanner which suports binary file formats, analysis of neste

STACS 81 Dec 27, 2022
Obfuscate your Python scripts better, faster.

⚜️ Berserker ⚜️ An unique Python3 obfuscator using Kyrie Eleison's encryption protocol, written in Python3. 📋 Examples 📋 Unobfuscated: input("Hello

Billy 81 Dec 07, 2022
Virus-Builder - This tool will generate a virus that can only destroy Windows computer

Virus-Builder - This tool will generate a virus that can only destroy Windows computer. You can also configure to auto run in usb drive

Saad 16 Dec 30, 2022
Undetectable Keylogger that reports to Discord

FUD Keylogger That Reports To Discord This python script will capture all of the keystrokes within a given time frame and report them to a Discord Ser

Dimitris Kalopisis 36 Dec 20, 2022
Xteam All in one Instagram,Android,phishing osint and wifi hacking tool available

Xteam All in one Instagram,Android,phishing osint and wifi hacking tool available

xploits tech 283 Dec 29, 2022
Finite Volume simulation of the Raleigh-Taylor Instability

finitevolume2-python Finite Volume simulation of the Raleigh-Taylor Instability Create Your Own Finite Volume Fluid Simulation (With Python): Part 2 B

Philip Mocz 12 Sep 01, 2022
Herramienta para descargar eventos de Sucuri WAF hacia disco.

Descarga los eventos de Sucuri Script para descargar los eventos del Sucuri Web Application Firewall (WAF) en el disco como archivos CSV. Requerimient

CSIRT-RD 2 Nov 29, 2021
MainCoon - an automated recon framework

MainCoon is an automated recon framework meant for gathering information during penetration testing of web applications.

Md. Nur habib 8 Aug 26, 2022
This exploit allows to connect to the remote RemoteMouse 3.008 service to virtually press arbitrary keys and execute code on the machine.

RemoteMouse-3.008-Exploit The RemoteMouse application is a program for remotely controlling a computer from a phone or tablet. This exploit allows to

Podalirius 25 Dec 04, 2022
RedlineSpam - Python tool to spam Redline Infostealer panels with legit looking data

RedlineSpam Python tool to spam Redline Infostealer panels with legit looking da

4 Jan 27, 2022
Android Malware (Analysis | Scoring) System

An Obfuscation-Neglect Android Malware Scoring System Quark-Engine is also bundled with Kali Linux, BlackArch. A trust-worthy, practical tool that's r

Quark-Engine 1k Jan 04, 2023
A python implementation of the windows 95 product key check.

Windows 95 Product Key Check Info: This is a python implementation of the windows 95 product key check. This was just a bit of fun and a massive 5 hou

11 Aug 07, 2022
Fast and easy way to rollout on multiple GitLab project file a particular content.

Volatile Fast and easy way to rollout on multiple GitLab project file a particular content. Why ? After looking for a tool to simply enforce a develop

Lujeni 4 Jan 17, 2022
Dlint is a tool for encouraging best coding practices and helping ensure Python code is secure.

Dlint Dlint is a tool for encouraging best coding practices and helping ensure Python code is secure. The most important thing I have done as a progra

Dlint 127 Dec 27, 2022