CVE-2023-36830

Prior to SQLFluff 2.1.2, untrusted users could execute arbitrary Python code via library_path in config files

• CVSS 7.8
• CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
• Input Validation and Sanitization
• Local

SQLFluff is a SQL linter. Prior to version 2.1.2, in environments where untrusted users have access to the config files, there is a potential security vulnerability where those users could use the `library_path` config value to allow arbitrary python code to be executed via macros. For many users who use SQLFluff in the context of an environment where all users already have fairly escalated privileges, this may not be an issue – however in larger user bases, or where SQLFluff is bundled into another tool where developers still wish to give users access to supply their on rule configuration, this may be an issue. The 2.1.2 release offers the ability for the `library_path` argument to be overwritten on the command line by using the `–library-path` option. This overrides any values provided in the config files and effectively prevents this route of attack for users which have access to the config file, but not to the scripts which call the SQLFluff CLI directly. A similar option is provided for the Python API, where users also have a greater ability to further customise or override configuration as necessary. Unless `library_path` is explicitly required, SQLFluff maintainers recommend using the option `–library-path none` when invoking SQLFluff which will disable the `library-path` option entirely regardless of the options set in the configuration file or via inline config directives. As a workaround, limiting access to – or otherwise validating configuration files before they are ingested by SQLFluff will provides a similar effect and does not require upgrade.

CVE

CVE-2023-36830

CWE

CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')

CVSS base score

7.8

Published

2023-07-06

OWASP

A05 Security Misconfiguration

Orthogonal defect classification

Function

Code defect classification

Incorrect Functionality

Category

Input Validation and Sanitization

Subcategory

Insecure Parsing or Deserialization

Accessibility scope

Local

Impact

Arbitrary Code Execution

Fixed by upgrading

Yes

Solution

Update SQLFluff to version 2.1.2 or higher.

import sqlfluff

config = {
    'library_path': '/path/to/user/supplied/library'
}

sqlfluff.lint("your_sql_file.sql", library_path=config['library_path'])

import argparse
import sqlfluff

def main():
    parser = argparse.ArgumentParser(description="Run SQLFluff with library path handling.")
    parser.add_argument('--library-path', default='none', help='Path to custom libraries for SQLFluff macros.')
    args = parser.parse_args()

    if args.library_path != 'none':
        print("Warning: Using a custom library path can introduce security vulnerabilities.")
        print("Setting library_path to 'none' for safety.")
        args.library_path = 'none'

    sqlfluff.lint("your_sql_file.sql", library_path=args.library_path)

if __name__ == "__main__":
    main()

@misc{vaitp:cve202336830,
  title        = {{Prior to SQLFluff 2.1.2, untrusted users could execute arbitrary Python code via library_path in config files}},
  author       = {Bogaerts, Fr\'ed\'eric and Ivaki, Naghmeh and Fonseca, Jos\'e},
  year         = {2023},
  note         = {VAITP Python Vulnerability Dataset, entry CVE-2023-36830},
  howpublished = {\url{https://netpack.pt/vaitp/vulnerability/CVE-2023-36830/}}
}