CVE-2023-29522

XWiki Platform: Remote code execution via script macros

• 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 can execute arbitrary script macros including Groovy and Python macros that allow remote code execution including unrestricted read and write access to all wiki contents. The attack works by opening a non-existing page with a name crafted to contain a dangerous payload. This issue has been patched in XWiki 14.4.8, 14.10.3 and 15.0RC1. Users are advised to upgrade. There are no known workarounds for this vulnerability.

CVE

CVE-2023-29522

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

A06 Vulnerable and Outdated Components

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 Platform to version 14.4.8, 14.10.3, or 15.0RC1.

def execute_macro(user_input):
    """Vulnerable function that demonstrates the security issue."""
    exec(user_input)

user_input = "import os; os.system('whoami')"
execute_macro(user_input)

def sanitize_input(user_input):
    """Secure function that fixes the vulnerability."""
    forbidden_patterns = ['$', '{', '}', '(', ')', 'import', 'exec', 'eval']
    for pattern in forbidden_patterns:
        if pattern in user_input:
            raise ValueError("Invalid input detected!")

    return user_input

def execute_macro(user_input):
    """Secure function that fixes the vulnerability."""
    sanitized_input = sanitize_input(user_input)

    safe_globals = {
        "__builtins__": {
            "print": print,
            "len": len
        }
    }

    exec(sanitized_input, safe_globals)

try:
    user_input = "import os; os.system('whoami')"
    execute_macro(user_input)
except ValueError as e:
    print(e)

@misc{vaitp:cve202329522,
  title        = {{XWiki Platform: Remote code execution via script macros}},
  author       = {Bogaerts, Fr\'ed\'eric and Ivaki, Naghmeh and Fonseca, Jos\'e},
  year         = {2023},
  note         = {VAITP Python Vulnerability Dataset, entry CVE-2023-29522},
  howpublished = {\url{https://netpack.pt/vaitp/vulnerability/CVE-2023-29522/}}
}