CVE-2020-15271 Explained : Impact and Mitigation

In lookatme (python/pypi package) versions prior to 2.3.0, the package automatically loaded the built-in 'terminal' and 'file_loader' extensions. Users that use lookatme to render untrusted markdown may have malicious shell commands automatically run on their system. This is fixed in version 2.3.0. As a workaround, the

lookatme/contrib/terminal.py

and

lookatme/contrib/file_loader.py

files may be manually deleted. Additionally, it is always recommended to be aware of what is being rendered with lookatme.

Understanding CVE-2020-15271

In this CVE, a vulnerability in the lookatme package allows for the automatic execution of malicious shell commands when rendering untrusted markdown content.

What is CVE-2020-15271?

The vulnerability in lookatme versions prior to 2.3.0 enables the automatic loading of certain extensions, leading to the execution of potentially harmful shell commands.

The Impact of CVE-2020-15271

CVSS Base Score: 9.3 (Critical)
Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: Required
Confidentiality Impact: High
Integrity Impact: High
Scope: Changed
Vector String: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N
This vulnerability poses a critical risk as it allows for the execution of arbitrary shell commands, potentially leading to unauthorized access and data compromise.

Technical Details of CVE-2020-15271

Vulnerability Description

The vulnerability stems from the automatic loading of 'terminal' and 'file_loader' extensions in lookatme versions prior to 2.3.0, enabling the execution of malicious shell commands.

Affected Systems and Versions

Affected Product: lookatme
Vendor: d0c-s4vage
Affected Versions: < 2.3.0

Exploitation Mechanism

The vulnerability can be exploited by crafting malicious markdown content that triggers the automatic execution of shell commands when rendered using lookatme.

Mitigation and Prevention

Immediate Steps to Take

Upgrade to version 2.3.0 or later to mitigate the vulnerability.
Manually delete the 'lookatme/contrib/terminal.py' and 'lookatme/contrib/file_loader.py' files as a temporary workaround.
Exercise caution when rendering untrusted markdown content with lookatme.

Long-Term Security Practices

Regularly update the lookatme package to the latest version to ensure all security patches are applied.
Implement input validation mechanisms to prevent the execution of unauthorized commands.

Patching and Updates

Ensure timely installation of patches and updates provided by the lookatme package maintainers to address security vulnerabilities.