CVE-2021-27760 : What You Need to Know

An authenticated Sametime chat user in HCL Notes version 11.0 - 11.0.1 FP4 could exploit a vulnerability to achieve Remote Code Execution on another chat client by sending a specially crafted message containing Javascript code.

Understanding CVE-2021-27760

This CVE relates to a security issue in the Sametime chat feature in HCL Notes 11.0 - 11.0.1 FP4 clients.

What is CVE-2021-27760?

CVE-2021-27760 is a vulnerability in HCL Notes that allows a Sametime chat user to execute remote code on another chat client through a maliciously crafted message.

The Impact of CVE-2021-27760

The impact of this vulnerability is deemed medium with a CVSS base score of 4.6. Exploiting this issue could lead to Remote Code Execution on a vulnerable chat client.

Technical Details of CVE-2021-27760

This section covers the technical details of the CVE.

Vulnerability Description

The vulnerability lies in the Sametime chat feature of HCL Notes 11.0 - 11.0.1 FP4 where a chat user can execute malicious code on another chat client.

Affected Systems and Versions

HCL Notes versions 11.0 to 11.0.1 FP4 are impacted by this vulnerability.

Exploitation Mechanism

An authenticated attacker can send a specially formatted message via chat, containing Javascript code to trigger Remote Code Execution on a target client.

Mitigation and Prevention

To address CVE-2021-27760 and prevent exploitation, consider the following measures.

Immediate Steps to Take

Update HCL Notes to a secure version that addresses the vulnerability.
Educate users on safe chat practices and avoid interacting with unknown or suspicious chat messages.

Long-Term Security Practices

Regularly update software to the latest patched versions to eliminate known vulnerabilities.
Implement network security measures to detect and prevent malicious chat activities.

Patching and Updates

Stay informed about security advisories from HCL Software and apply patches promptly to secure your systems.