CVE-2025-30416: Acronis Cyber Protect Auth Bypass Flaw

CVE-2025-30416 Overview

CVE-2025-30416 is a critical Missing Authorization vulnerability affecting Acronis Cyber Protect products. The vulnerability enables sensitive data disclosure and manipulation due to missing authorization controls in the application. Attackers can exploit this flaw to access and modify sensitive data without proper authentication or authorization checks, potentially compromising the integrity and confidentiality of protected backup infrastructure.

Critical Impact

This vulnerability allows unauthenticated remote attackers to access and manipulate sensitive data in Acronis Cyber Protect environments, potentially leading to complete compromise of backup infrastructure and protected systems.

Affected Products

• Acronis Cyber Protect 16 (Linux, Windows) before build 39938
• Acronis Cyber Protect 15 (Linux, Windows) before build 41800

Discovery Timeline

• 2026-02-20 - CVE-2025-30416 published to NVD
• 2026-02-20 - Last updated in NVD database

Technical Details for CVE-2025-30416

Vulnerability Analysis

This vulnerability is classified as CWE-862 (Missing Authorization), indicating that the affected Acronis Cyber Protect application fails to perform proper authorization checks before allowing access to sensitive functionality or data. The flaw is particularly severe because it can be exploited remotely over the network without requiring any prior authentication or user interaction.

The vulnerability affects backup and disaster recovery infrastructure, which typically contains highly sensitive organizational data including system images, file backups, and configuration information. Successful exploitation could allow attackers to exfiltrate confidential backup data, modify backup configurations, or potentially inject malicious content into backup repositories.

Root Cause

The root cause of CVE-2025-30416 is the absence of proper authorization validation in certain application endpoints or functionality within Acronis Cyber Protect. When authorization checks are missing, the application fails to verify whether a requesting entity has the appropriate permissions to access or modify resources, effectively bypassing access control mechanisms entirely.

This type of vulnerability typically occurs when developers assume that authentication alone is sufficient, or when certain API endpoints or administrative functions are inadvertently left unprotected during development.

Attack Vector

The attack vector is network-based, allowing remote exploitation without authentication requirements. An attacker can directly interact with the vulnerable Acronis Cyber Protect instance over the network to exploit the missing authorization controls.

The exploitation flow typically involves:

1. Identifying an exposed Acronis Cyber Protect instance on the network
2. Sending crafted requests to endpoints that lack authorization checks
3. Accessing or modifying sensitive data such as backup configurations, credentials, or backup data itself
4. Potentially escalating access to compromise protected systems through manipulated backups

For technical details on the specific vulnerable endpoints and exploitation mechanics, refer to the Acronis Security Advisory SEC-8766.

Detection Methods for CVE-2025-30416

Indicators of Compromise

• Unexpected API calls or requests to Acronis Cyber Protect management interfaces from unauthorized IP addresses
• Anomalous access patterns to backup repositories or configuration data
• Unauthorized modifications to backup schedules, retention policies, or agent configurations
• Evidence of data exfiltration from backup storage locations

Detection Strategies

• Monitor network traffic for unusual connections to Acronis Cyber Protect management ports
• Implement logging and alerting on all administrative actions within the Acronis console
• Review access logs for requests that bypass normal authentication workflows
• Deploy network intrusion detection signatures to identify exploitation attempts

Monitoring Recommendations

• Enable comprehensive audit logging within Acronis Cyber Protect and forward logs to a centralized SIEM
• Configure alerts for any unauthorized access attempts or privilege escalation events
• Monitor for changes to critical backup configurations outside of approved change windows
• Implement file integrity monitoring on Acronis Cyber Protect installation directories

How to Mitigate CVE-2025-30416

Immediate Actions Required

• Upgrade Acronis Cyber Protect 16 to build 39938 or later immediately
• Upgrade Acronis Cyber Protect 15 to build 41800 or later immediately
• Restrict network access to Acronis Cyber Protect management interfaces to trusted administrative networks only
• Review recent access logs for signs of unauthorized access or data manipulation

Patch Information

Acronis has released security patches addressing this vulnerability. Organizations running affected versions should apply the updates as soon as possible:

• Acronis Cyber Protect 16: Update to build 39938 or later
• Acronis Cyber Protect 15: Update to build 41800 or later

For detailed patch information and download links, consult the Acronis Security Advisory SEC-8766.

Workarounds

• Implement network segmentation to isolate Acronis Cyber Protect instances from untrusted networks
• Deploy a web application firewall (WAF) or reverse proxy with strict access controls in front of the management interface
• Enable IP allowlisting to restrict access to known administrative hosts only
• Consider temporarily disabling external network access to Acronis Cyber Protect until patches can be applied

# Example: Restrict access to Acronis management interface using iptables
# Allow only trusted admin network (adjust IP range as needed)
iptables -A INPUT -p tcp --dport 9877 -s 10.0.0.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 9877 -j DROP

# For Windows environments, configure Windows Firewall rules
# to restrict inbound connections to management ports