CVE-2020-27643 : Security Advisory and Response

1E Client 5.0.0.745 and 4.1.0.267 allows users to create and modify files in protected directories, leading to partial privilege escalation.

Understanding CVE-2020-27643

What is CVE-2020-27643?

The vulnerability in 1E Client allows remote authenticated and local users to manipulate files in restricted directories by creating a junction point to a system directory, resulting in partial privilege escalation.

The Impact of CVE-2020-27643

The security flaw enables unauthorized users to access and modify files in protected areas, potentially leading to unauthorized system changes and data compromise.

Technical Details of CVE-2020-27643

Vulnerability Description

The issue arises from the improper handling of directory permissions in 1E Client, allowing users to bypass restrictions and gain unauthorized access to system directories.

Affected Systems and Versions

Affected Versions: 1E Client 5.0.0.745 and 4.1.0.267

Exploitation Mechanism

By creating a junction point to a system directory within %PROGRAMDATA%\1E\Client, users can circumvent normal access controls and manipulate files in protected directories.

Mitigation and Prevention

Immediate Steps to Take

Apply vendor-supplied patches or updates promptly to address the vulnerability.
Monitor system logs for any suspicious file modifications or unauthorized access attempts.

Long-Term Security Practices

Implement the principle of least privilege to restrict user access rights and minimize the impact of potential security breaches.
Conduct regular security audits and assessments to identify and remediate vulnerabilities proactively.

Patching and Updates

Regularly update 1E Client to the latest version to ensure that known security issues are patched and system integrity is maintained.