CVE-2023-39659

Arbitrary code execution in langchain-ai (v0.0.232 and earlier) via PythonAstREPLTool._run component

• CVSS 9.8
• CWE-74
• Input Validation and Sanitization
• Remote

An issue in langchain langchain-ai v.0.0.232 and before allows a remote attacker to execute arbitrary code via a crafted script to the PythonAstREPLTool._run component.

CVE

CVE-2023-39659

CWE

CWE-74

CVSS base score

9.8

Published

2023-08-15

OWASP

A03 Injection

Orthogonal defect classification

Interface

Code defect classification

Incorrect Interface

Category

Input Validation and Sanitization

Subcategory

Insecure Parsing or Deserialization

Accessibility scope

Remote

Impact

Arbitrary Code Execution

Fixed by upgrading

Yes

Solution

Update to langchain-ai version 0.0.233 or higher

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")

@misc{vaitp:cve202339659,
  title        = {{Arbitrary code execution in langchain-ai (v0.0.232 and earlier) via PythonAstREPLTool._run component}},
  author       = {Bogaerts, Fr\'ed\'eric and Ivaki, Naghmeh and Fonseca, Jos\'e},
  year         = {2023},
  note         = {VAITP Python Vulnerability Dataset, entry CVE-2023-39659},
  howpublished = {\url{https://netpack.pt/vaitp/vulnerability/CVE-2023-39659/}}
}