CVE-2021-42771 Explained : Impact and Mitigation

Babel.Locale in Babel before 2.9.1 allows attackers to load arbitrary locale .dat files via directory traversal, leading to code execution.

Understanding CVE-2021-42771

Babel.Locale in Babel before version 2.9.1 is vulnerable to a directory traversal attack that enables the loading of malicious locale .dat files, resulting in the execution of arbitrary code.

What is CVE-2021-42771?

The vulnerability in Babel.Locale allows threat actors to exploit directory traversal to inject and execute code through the loading of unauthorized locale .dat files.

The Impact of CVE-2021-42771

This vulnerability can lead to severe consequences, enabling attackers to execute arbitrary code on the affected system, potentially compromising data integrity and system security.

Technical Details of CVE-2021-42771

Babel.Locale in Babel version 2.9.1 and earlier is susceptible to this security flaw.

Vulnerability Description

The issue arises from the improper handling of locale .dat files, allowing malicious actors to upload files containing serialized Python objects.

Affected Systems and Versions

Product: Babel
Vendor: N/A
Versions affected: Babel versions before 2.9.1

Exploitation Mechanism

By exploiting directory traversal, attackers can manipulate the loading of unauthorized locale .dat files, leveraging them to execute arbitrary code.

Mitigation and Prevention

It is crucial to take immediate action to mitigate the risks posed by CVE-2021-42771.

Immediate Steps to Take

Update Babel to version 2.9.1 or later to patch the vulnerability.
Monitor for any signs of unauthorized access or unusual file activity.

Long-Term Security Practices

Implement robust input validation mechanisms to prevent directory traversal attacks.
Regularly audit and review file upload functionalities for security loopholes.

Patching and Updates

Apply all recommended security patches promptly.