CVE-2023-29516

XWiki Platform: Code Execution via Improper Escaping

• CVSS 8.8
• CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
• Input Validation and Sanitization
• Remote

XWiki Platform is a generic wiki platform offering runtime services for applications built on top of it. Any user with view rights on `XWiki.AttachmentSelector` can execute arbitrary Groovy, Python or Velocity code in XWiki leading to full access to the XWiki installation. The root cause is improper escaping in the "Cancel and return to page" button. This page is installed by default. This vulnerability has been patched in XWiki 15.0-rc-1, 14.10.1, 14.4.8, and 13.10.11. There are no known workarounds for this vulnerability.

CVE

CVE-2023-29516

CWE

CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')

CVSS base score

8.8

Published

2023-04-19

OWASP

A03 Injection

Orthogonal defect classification

Function

Code defect classification

Incorrect Functionality

Category

Input Validation and Sanitization

Subcategory

Command Injection

Accessibility scope

Remote

Impact

Arbitrary Code Execution

Fixed by upgrading

Yes

Solution

Update XWiki to version 15.0-rc-1, 14.10.1, 14.4.8, or 13.10.11.

def render_button(user_input):
    return f'<button onclick="{user_input}">Cancel and return to page</button>'

user_input = "returnToPage(); alert('XSS Vulnerability!');"
html_output = render_button(user_input)
print(html_output)

def render_button(user_input):
    button_label = escape_html(user_input)
    return f'<button onclick="{button_label}">Cancel and return to page</button>'

def escape_html(text):
    return (text.replace("&", "&")
                .replace("<", "<")
                .replace(">", ">")
                .replace('"', """)
                .replace("'", "'"))


user_input = "returnToPage(); alert('XSS Vulnerability!');"
html_output = render_button(user_input)
print(html_output)

@misc{vaitp:cve202329516,
  title        = {{XWiki Platform: Code Execution via Improper Escaping}},
  author       = {Bogaerts, Fr\'ed\'eric and Ivaki, Naghmeh and Fonseca, Jos\'e},
  year         = {2023},
  note         = {VAITP Python Vulnerability Dataset, entry CVE-2023-29516},
  howpublished = {\url{https://netpack.pt/vaitp/vulnerability/CVE-2023-29516/}}
}