CVE-2023-1720 : What You Need to Know

This CVE-2023-1720 discusses a vulnerability in Bitrix24 that allows authenticated remote attackers to execute arbitrary JavaScript code in the victim's browser and potentially execute arbitrary PHP code on the server under certain conditions.

Understanding CVE-2023-1720

This section delves into the specifics of CVE-2023-1720, shedding light on the vulnerability's nature and its implications.

What is CVE-2023-1720?

The vulnerability stems from a lack of mime type response header in Bitrix24 version 22.0.300. Attackers with remote access can upload a specially crafted HTML file through

/desktop_app/file.ajax.php?action=uploadfile

, exploiting this flaw to execute malicious JavaScript code in the victim's browser.

The Impact of CVE-2023-1720

The impact of this vulnerability is significant, as attackers can conduct stored cross-site scripting (XSS) attacks, potentially compromising the confidentiality, integrity, and availability of the affected systems.

Technical Details of CVE-2023-1720

This section provides a closer look at the technical aspects of CVE-2023-1720, including its description, affected systems and versions, and the exploitation mechanism.

Vulnerability Description

The vulnerability allows authenticated remote attackers to upload a crafted HTML file to execute arbitrary JavaScript code in the victim's browser and possibly arbitrary PHP code on the server.

Affected Systems and Versions

Bitrix24 version 22.0.300 is confirmed to be affected by this vulnerability. Other versions may not be impacted.

Exploitation Mechanism

By exploiting the lack of mime type response header, attackers can upload specially crafted HTML files to execute malicious code on both the victim's browser and potentially on the server.

Mitigation and Prevention

In light of CVE-2023-1720, it is crucial to implement mitigation strategies to reduce the risk of exploitation and enhance the overall security posture of the systems.

Immediate Steps to Take

Update Bitrix24 to a version where the vulnerability has been patched.
Restrict access to the vulnerable endpoint

/desktop_app/file.ajax.php?action=uploadfile

.
Educate users on safe file handling practices to prevent uploading of malicious files.

Long-Term Security Practices

Implement regular security assessments and penetration testing to identify and address vulnerabilities proactively.
Stay informed about security best practices and emerging threats in the cybersecurity landscape.

Patching and Updates

Ensure timely application of security patches and updates provided by Bitrix24 to mitigate known vulnerabilities and enhance system security. Regularly monitor for security advisories and apply patches promptly to stay protected.