CVE-2022-36099

Arbitrary script injection in XWiki Platform Wiki

• CVSS 8.8
• CWE-116
• Input Validation and Sanitization
• Remote

XWiki Platform Wiki UI Main Wiki is software for managing subwikis on XWiki Platform, a generic wiki platform. Starting with version 5.3-milestone-2 and prior to versions 13.10.6 and 14.4, it's possible to inject arbitrary wiki syntax including Groovy, Python and Velocity script macros via the request (URL parameter) using the `XWikiServerClassSheet` if the user has view access to this sheet and another page that has been saved with programming rights, a standard condition on a public read-only XWiki installation or a private XWiki installation where the user has an account. This allows arbitrary Groovy/Python/Velocity code execution which allows bypassing all rights checks and thus both modification and disclosure of all content stored in the XWiki installation. Also, this could be used to impact the availability of the wiki. This has been patched in versions 13.10.6 and 14.4. As a workaround, edit the affected document `XWiki.XWikiServerClassSheet` or `WikiManager.XWikiServerClassSheet` and manually perform the changes from the patch fixing the issue. On XWiki versions 12.0 and later, it is also possible to import the document `XWiki.XWikiServerClassSheet` from the xwiki-platform-wiki-ui-mainwiki package version 14.4 using the import feature of the administration application as there have been no other changes to this document since XWiki 12.0.

CVE

CVE-2022-36099

CWE

CWE-116

CVSS base score

8.8

Published

2022-09-08

OWASP

A01 Broken Access Control

Orthogonal defect classification

Function

Code defect classification

Incorrect Functionality

Category

Input Validation and Sanitization

Subcategory

Insecure Direct Object References (IDOR)

Accessibility scope

Remote

Impact

Arbitrary Code Execution

Fixed by upgrading

Yes

Solution

Upgrade to XWiki versions 13.10.6 or 14.4 to patch the vulnerability.

from flask import Flask, request

app = Flask(__name__)

def render_wiki_content(wiki_code):
    """Vulnerable function that demonstrates the security issue."""
    exec(wiki_code)

@app.route('/execute', methods=['GET'])
def execute_code():
    """Vulnerable function that demonstrates the security issue."""
    user_input = request.args.get('code')
    if user_has_view_access():
        render_wiki_content(user_input)
        return "Code executed!"
    else:
        return "Access denied!", 403

def user_has_view_access():
    """Vulnerable function that demonstrates the security issue."""
    return True

if __name__ == '__main__':
    app.run(debug=False)

from flask import Flask, request

app = Flask(__name__)

def render_wiki_content(user, script, allowed_scripts):
    """Secure function that fixes the vulnerability."""
    # SECURE: This version prevents command injection
    if not user.has_permission('execute_scripts'):
        raise PermissionError("User  does not have permission to execute scripts.")

    if script not in allowed_scripts:
        raise ValueError("Script execution is not allowed.")

    try:
        exec(script)
    except Exception as e:
        raise RuntimeError(f"Script execution failed: {e}")

allowed_scripts = [
    'print("Hello, world!")',
    'x = 5\nprint(x * 2)'
]

@app.route('/execute', methods=['GET'])
def execute_code():
    """Secure function that fixes the vulnerability."""
    user_input = request.args.get('code')
    if user_has_view_access():
        render_wiki_content(user_input)
        return "Code executed!"
    else:
        return "Access denied!", 403

def user_has_view_access():
    """Secure function that fixes the vulnerability."""
    return True


if __name__ == '__main__':
    app.run(debug=False)

@misc{vaitp:cve202236099,
  title        = {{Arbitrary script injection in XWiki Platform Wiki}},
  author       = {Bogaerts, Fr\'ed\'eric and Ivaki, Naghmeh and Fonseca, Jos\'e},
  year         = {2022},
  note         = {VAITP Python Vulnerability Dataset, entry CVE-2022-36099},
  howpublished = {\url{https://netpack.pt/vaitp/vulnerability/CVE-2022-36099/}}
}