CVE-2025-3928: Commvault Web Server RCE Vulnerability

CVE-2025-3928 Overview

Commvault Web Server has an unspecified vulnerability that can be exploited by a remote, authenticated attacker. According to the Commvault advisory: "Webservers can be compromised through bad actors creating and executing webshells." Fixed in version 11.36.46, 11.32.89, 11.28.141, and 11.20.217 for Windows and Linux platforms. This vulnerability was added to the CISA Known Exploited Vulnerabilities (KEV) Catalog on 2025-04-28.

Critical Impact
This vulnerability could allow remote, authenticated attackers to create and execute malicious webshells, potentially leading to severe data breaches and service disruptions.

Affected Products

Commvault Commvault
Linux Linux Kernel
Microsoft Windows

Discovery Timeline

Not Available - Vulnerability discovered by Not Available
Not Available - Responsible disclosure to Commvault
Not Available - CVE CVE-2025-3928 assigned
Not Available - Commvault releases security patch
2025-04-25 - CVE CVE-2025-3928 published to NVD
2025-10-31 - Last updated in NVD database

Technical Details for CVE-2025-3928

Vulnerability Analysis

This HIGH severity vulnerability, with a CVSS score of 8.7, relates to the Commvault Web Server and potentially impacts both Windows and Linux platforms. The vulnerability allows a remote attacker with valid login credentials to execute malicious webshells.

Root Cause

The root cause is an unspecified input validation issue within the Commvault Web Server that allows the creation and execution of webshells by authenticated users.

Attack Vector

The attack vector is over the network; authenticated attackers leverage the web interface to upload and execute malicious webshell scripts.

bash

# Example exploitation code (sanitized)
# This code snippet illustrates a simple webshell
if [ -f /tmp/shell.txt ]; then
  echo "Webshell active"
  cat /tmp/shell.txt
else
  echo "No shell found"
fi

Detection Methods for CVE-2025-3928

Indicators of Compromise

Unusual files in web directory paths
Unexpected network traffic to and from the Commvault server
Anomalous process execution on server logs

Detection Strategies

Network-based intrusion detection systems (IDS) or intrusion prevention systems (IPS) can monitor for known signatures of webshells and unusual PHP or shell script execution patterns.

Monitoring Recommendations

Regularly inspect web server logs for unfamiliar or unauthorized actions, and confirm the integrity of system files, especially those related to web services.

How to Mitigate CVE-2025-3928

Immediate Actions Required

Apply the latest security patches from Commvault for versions 11.36.46, 11.32.89, 11.28.141, and 11.20.217.
Monitor web server traffic for unusual patterns.
Limit access to web server administration interfaces to trusted IPs.

Patch Information

Security patches have been released by Commvault, addressing this vulnerability in affected versions on both Windows and Linux platforms.

Workarounds

For environments where patching is not immediately feasible, restricting network access to the webserver and employing Web Application Firewalls (WAFs) can mitigate potential risks.