CVE-2020-15843 : Security Advisory and Response

ActFax Version 7.10 Build 0335 is vulnerable to a privilege escalation issue due to insecure folder permissions. An attacker can exploit this to replace critical binaries, potentially leading to unauthorized access.

Understanding CVE-2020-15843

ActFax Version 7.10 Build 0335 has a security vulnerability that allows for privilege escalation through insecure folder permissions.

What is CVE-2020-15843?

The vulnerability in ActFax Version 7.10 Build 0335 enables an authenticated local attacker to escalate privileges by manipulating critical binaries in specific directories with insecure permissions.

The Impact of CVE-2020-15843

The vulnerability can be exploited by an attacker to gain unauthorized access and potentially execute malicious actions on the system, compromising its integrity and confidentiality.

Technical Details of CVE-2020-15843

ActFax Version 7.10 Build 0335 vulnerability details.

Vulnerability Description

ActFax Version 7.10 Build 0335 has insecure folder permissions in %PROGRAMFILES%\ActiveFax\Client, %PROGRAMFILES%\ActiveFax\Install, and %PROGRAMFILES%\ActiveFax\Terminal, allowing 'Full Control' to 'Everyone'.
An attacker can replace critical binaries like TSClientB.exe in the Terminal directory, executed on user logon, or other binaries in Client or Install directories.

Affected Systems and Versions

Product: ActFax Version 7.10 Build 0335
Vendor: Not specified
Affected Version: Not specified

Exploitation Mechanism

An authenticated local attacker can exploit the insecure folder permissions to replace critical binaries, potentially leading to privilege escalation and unauthorized access.
The attacker can manipulate the Terminal directory's TSClientB.exe binary or other binaries in Client or Install directories.
Additional user interaction may be required for replacing binaries in Client or Install directories.

Mitigation and Prevention

Steps to mitigate and prevent CVE-2020-15843.

Immediate Steps to Take

Restrict access to critical directories and files to authorized users only.
Regularly monitor file integrity and permissions to detect unauthorized changes.
Implement the principle of least privilege to limit user access rights.

Long-Term Security Practices

Conduct regular security audits and vulnerability assessments to identify and address security gaps.
Educate users on secure practices and the importance of maintaining secure file permissions.

Patching and Updates

Apply patches and updates provided by the vendor to address the vulnerability and enhance system security.