CVE-2024-56201

Jinja template injection allows arbitrary code execution via controlled filename and content.

• CVSS 5.4
• CWE-150
• Design Defects
• Remote

Jinja is an extensible templating engine. Prior to 3.1.5, a bug in the Jinja compiler allows an attacker that controls both the content and filename of a template to execute arbitrary Python code, regardless of if Jinja's sandbox is used. To exploit the vulnerability, an attacker needs to control both the filename and the contents of a template. Whether that is the case depends on the type of application using Jinja. This vulnerability impacts users of applications which execute untrusted templates where the template author can also choose the template filename. This vulnerability is fixed in 3.1.5.

CVE

CVE-2024-56201

CWE

CWE-150

CVSS base score

5.4

Published

2024-12-23

OWASP

A03 Injection

Orthogonal defect classification

Algorithm

Code defect classification

Incorrect Algorithm

Category

Design Defects

Subcategory

Insecure Parsing or Deserialization

Accessibility scope

Remote

Impact

Arbitrary Code Execution

Affected component

Jinja

Fixed by upgrading

Yes

Solution

Upgrade to Jinja 3.1.5 or later.

def calculate(expression):
    """Calculate expression - VULNERABLE to code injection"""
    # VULNERABILITY: eval() executes arbitrary Python code
    return eval(expression)

# Example exploitation:
# calculate("__import__('os').system('whoami')")

import ast
import operator

def calculate_secure(expression):
    """Securely calculate mathematical expression"""
    try:
        # Parse expression into AST
        tree = ast.parse(expression, mode='eval')
        return eval_ast_node(tree.body)
    except:
        return None

def eval_ast_node(node):
    """Safely evaluate AST node"""
    if isinstance(node, ast.Constant):
        return node.value
    elif isinstance(node, ast.BinOp):
        left = eval_ast_node(node.left)
        right = eval_ast_node(node.right)
        ops = {ast.Add: operator.add, ast.Sub: operator.sub}
        return ops[type(node.op)](left, right)
    else:
        raise ValueError("Unsupported operation")

{% set x = namespace() %}
{% set x.filename = "__import__('os').system('touch /tmp/pwned')" %}
{{ include(x.filename) }}

@misc{vaitp:cve202456201,
  title        = {{Jinja template injection allows arbitrary code execution via controlled filename and content.
}},
  author       = {Bogaerts, Fr\'ed\'eric and Ivaki, Naghmeh and Fonseca, Jos\'e},
  year         = {2024},
  note         = {VAITP Python Vulnerability Dataset, entry CVE-2024-56201},
  howpublished = {\url{https://netpack.pt/vaitp/vulnerability/CVE-2024-56201/}}
}