CVE-2025-57791: Commvault RCE Vulnerability

CVE-2025-57791 Overview

CVE-2025-57791 is an argument injection vulnerability [CWE-88] in Commvault that allows remote attackers to inject or manipulate command-line arguments passed to internal components. The flaw stems from insufficient input validation on data received from network requests. Successful exploitation produces a valid user session with a low-privilege role, giving unauthenticated attackers an initial foothold inside the application. Commvault published security advisory CV_2025_08_1 describing the issue and the affected versions.

Critical Impact

Remote, unauthenticated attackers can manipulate internal command-line arguments to obtain a valid low-privilege session within Commvault, providing a launching point for follow-on attacks against backup infrastructure.

Affected Products

• Commvault (see vendor advisory CV_2025_08_1 for the affected version range)
• Commvault on-premises deployments exposed to network-reachable users
• Commvault web-facing components processing client-supplied parameters

Discovery Timeline

• 2025-08-20 - CVE-2025-57791 published to the National Vulnerability Database (NVD)
• 2025-09-10 - Last updated in NVD database

Technical Details for CVE-2025-57791

Vulnerability Analysis

The vulnerability is classified under [CWE-88] Improper Neutralization of Argument Delimiters in a Command, commonly referred to as argument injection. Commvault accepts attacker-controlled input from network requests and forwards it into command-line invocations of internal components without adequate sanitization. Because argument boundaries are not enforced, an attacker can introduce additional flags or modify existing ones consumed by the downstream component.

The attack does not require authentication or user interaction and is reachable over the network. The outcome of successful exploitation is the establishment of an authenticated session with a low-privilege role. While the immediate confidentiality and integrity impact is limited, the resulting session can be combined with other weaknesses to expand access inside the backup environment.

The EPSS data for this CVE indicates a notably high probability of exploitation activity relative to other vulnerabilities, which warrants prioritized remediation despite the medium severity rating.

Root Cause

The root cause is missing or insufficient validation of user-supplied parameters before they are concatenated into command-line argument lists. The application trusts that downstream parsers will correctly tokenize input, but attacker-supplied delimiters and option prefixes cause arguments to be reinterpreted as flags. This allows logic flow manipulation in the invoked internal component, including bypassing controls that gate authentication state.

Attack Vector

The attack vector is network-based and unauthenticated. An attacker sends a crafted request to an exposed Commvault endpoint with parameters that embed argument delimiters or option-style tokens. The injected arguments alter the behavior of internal command-line components, ultimately producing a session token tied to a low-privilege role. No client-side interaction is required.

No public proof-of-concept or exploit code is currently available for CVE-2025-57791. The vendor advisory at Commvault Security Advisory CV_2025_08_1 provides additional context for defenders.

Detection Methods for CVE-2025-57791

Indicators of Compromise

• Unexpected creation of low-privilege Commvault user sessions originating from external or unusual source IP addresses.
• HTTP request parameters containing argument delimiter characters such as --, leading dashes, or shell metacharacters targeting Commvault endpoints.
• Anomalous invocations of internal Commvault command-line utilities with unusual flag combinations.

Detection Strategies

• Review Commvault web server and application logs for requests containing argument-style tokens in fields that should accept only opaque identifiers or simple strings.
• Correlate session-creation events with the originating request payload to identify sessions established outside normal authentication flows.
• Baseline expected command-line arguments for Commvault internal components and alert on deviations.

Monitoring Recommendations

• Enable verbose audit logging on Commvault management interfaces and forward logs to a central analysis platform.
• Monitor for new low-privilege accounts or sessions created without a preceding successful interactive login.
• Track outbound activity from Commvault hosts following session creation, since attackers commonly pivot from initial low-privilege footholds.

How to Mitigate CVE-2025-57791

Immediate Actions Required

• Apply the fixed Commvault version listed in Commvault Security Advisory CV_2025_08_1 as soon as possible.
• Restrict network exposure of Commvault management and web interfaces to trusted administrative networks only.
• Audit existing Commvault user accounts and sessions for unexpected low-privilege identities and revoke any that cannot be attributed.

Patch Information

Commvault has published security advisory CV_2025_08_1 with remediation details and affected version information. Administrators should consult the advisory at Commvault Security Advisory CV_2025_08_1 to identify the correct fixed release for their deployment and follow the vendor's documented upgrade procedure.

Workarounds

• Place Commvault web-facing endpoints behind a reverse proxy or web application firewall that strips or rejects argument-delimiter characters in request parameters.
• Limit access to Commvault interfaces using network ACLs, VPN gating, or zero-trust network access until the patch is deployed.
• Increase logging verbosity and monitoring on Commvault systems to shorten detection time for attempted exploitation.

# Example: restrict Commvault web interface access to a trusted management subnet
iptables -A INPUT -p tcp --dport 443 -s 10.10.50.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP