CVE-2025-15610: RightFax Deserialization Vulnerability

CVE-2025-15610 Overview

CVE-2025-15610 is a critical deserialization of untrusted data vulnerability affecting OpenText RightFax on Windows systems (both 32-bit and 64-bit architectures). This vulnerability allows attackers to perform Object Injection attacks, potentially leading to remote code execution, unauthorized data access, or complete system compromise. The flaw exists due to improper handling of serialized data, enabling malicious actors to inject arbitrary objects into the application's execution flow.

Critical Impact

This vulnerability enables unauthenticated remote attackers to inject malicious objects through deserialization, potentially achieving complete system compromise with high impact to confidentiality, integrity, and availability.

Affected Products

• OpenText RightFax through version 25.4 (Windows 64-bit)
• OpenText RightFax through version 25.4 (Windows 32-bit)

Discovery Timeline

• 2026-04-15 - CVE-2025-15610 published to NVD
• 2026-04-15 - Last updated in NVD database

Technical Details for CVE-2025-15610

Vulnerability Analysis

This vulnerability falls under CWE-502 (Deserialization of Untrusted Data), a well-known class of security flaws that occurs when applications deserialize data from untrusted sources without adequate validation. In the context of OpenText RightFax, the application fails to properly validate or sanitize serialized input before processing it, creating a pathway for Object Injection attacks.

The network-accessible nature of this vulnerability means attackers can exploit it remotely without requiring any authentication or user interaction. When successfully exploited, an attacker can achieve high-impact consequences across all three security pillars: confidentiality, integrity, and availability of the affected system.

Root Cause

The root cause of CVE-2025-15610 lies in the improper handling of serialized data within OpenText RightFax. The application accepts and processes serialized objects from external sources without implementing adequate input validation, type checking, or integrity verification. This allows attackers to craft malicious serialized payloads containing arbitrary objects that, when deserialized by the vulnerable application, execute unintended operations.

Deserialization vulnerabilities are particularly dangerous because they can bypass traditional input validation mechanisms—the malicious payload is embedded within what appears to be legitimate serialized data, only revealing its true nature during the deserialization process.

Attack Vector

The attack vector for this vulnerability is network-based, requiring no privileges or user interaction. An attacker can exploit this vulnerability by:

1. Crafting a malicious serialized payload containing injected objects designed to execute arbitrary code or perform unauthorized actions
2. Sending the payload to the vulnerable RightFax service over the network
3. The application deserializes the untrusted data, instantiating the malicious objects
4. The injected objects execute their payload, potentially granting the attacker full control of the system

The exploitation mechanism leverages the application's trust in serialized data structures. When the RightFax application processes the malicious payload, it reconstructs the attacker-controlled objects, which can trigger dangerous operations such as command execution, file system access, or data exfiltration. For detailed technical information, refer to the OpenText Unauthenticated Access Advisory.

Detection Methods for CVE-2025-15610

Indicators of Compromise

• Unusual network traffic patterns to RightFax services, particularly containing serialized data structures
• Unexpected process spawning or command execution originating from RightFax application processes
• Anomalous file system access or modifications in RightFax directories
• Authentication bypass events or unauthorized access to RightFax functionality
• Log entries showing deserialization errors or object instantiation failures

Detection Strategies

• Monitor network traffic for suspicious serialized payloads targeting RightFax services
• Implement application-level logging to detect unusual deserialization activities
• Deploy endpoint detection and response (EDR) solutions to identify post-exploitation behaviors
• Use intrusion detection systems (IDS) with signatures for known deserialization attack patterns
• Audit RightFax service accounts for signs of unauthorized activity or privilege escalation

Monitoring Recommendations

• Enable verbose logging on RightFax servers to capture detailed request information
• Monitor process trees for unexpected child processes spawned by RightFax services
• Implement file integrity monitoring on critical RightFax directories and configuration files
• Set up alerts for network connections from RightFax services to unusual external destinations

How to Mitigate CVE-2025-15610

Immediate Actions Required

• Review and restrict network access to RightFax services using firewall rules
• Implement network segmentation to isolate RightFax servers from untrusted networks
• Apply input validation at the network perimeter using web application firewalls (WAF)
• Audit current RightFax deployments to identify all affected instances
• Monitor for exploitation attempts while awaiting official patches

Patch Information

OpenText has released information regarding this vulnerability. Administrators should consult the OpenText Unauthenticated Access Advisory for official guidance on remediation steps and available patches. It is critical to upgrade RightFax installations beyond version 25.4 once a patched version is available, or apply any vendor-provided hotfixes immediately.

Workarounds

• Restrict network access to RightFax services to only trusted IP addresses and networks
• Implement additional authentication layers in front of RightFax services where possible
• Deploy runtime application self-protection (RASP) solutions to detect and block deserialization attacks
• Consider temporarily disabling non-essential RightFax functionality until patches are applied

# Example: Windows Firewall rule to restrict RightFax access
# Adjust port numbers based on your RightFax configuration
netsh advfirewall firewall add rule name="Restrict RightFax Access" ^
    dir=in action=allow protocol=TCP localport=<RIGHTFAX_PORT> ^
    remoteip=<TRUSTED_IP_RANGE>