CVE-2025-63912: Cohesity Tranzman Weak Cryptography Flaw

CVE-2025-63912 Overview

CVE-2025-63912 is a weak cryptography vulnerability discovered in the Cohesity TranZman Migration Appliance Release 4.0 Build 14614. The appliance was found to employ an insufficiently strong cryptographic algorithm for data encryption, enabling attackers to trivially reverse the encryption and expose sensitive credentials. This vulnerability falls under CWE-327 (Use of a Broken or Risky Cryptographic Algorithm).

Critical Impact

Attackers with network access can decrypt sensitive credential data stored or transmitted by the TranZman appliance, potentially compromising the entire data migration infrastructure and connected systems.

Affected Products

• Cohesity TranZman Migration Appliance Release 4.0 Build 14614
• cohesity:tranzman version 4.0:build14614

Discovery Timeline

• 2026-03-03 - CVE-2025-63912 published to NVD
• 2026-03-05 - Last updated in NVD database

Technical Details for CVE-2025-63912

Vulnerability Analysis

This vulnerability stems from the use of weak cryptographic algorithms within the Cohesity TranZman Migration Appliance. The appliance relies on cryptographic protections to secure sensitive data, including stored credentials used during data migration operations. However, the implementation uses an algorithm that is considered cryptographically weak by modern security standards.

The weakness allows an attacker who can intercept or access encrypted data to reverse the encryption process without requiring the original encryption key. Since the TranZman appliance is a migration tool that handles data transfers between storage systems, the credentials it stores may include administrative access to source and destination storage infrastructure.

The network-accessible nature of this vulnerability means that remote attackers can potentially exploit it without requiring authentication or user interaction. Once credentials are extracted, attackers could gain unauthorized access to connected storage systems, data repositories, and backup infrastructure.

Root Cause

The root cause of CVE-2025-63912 is the implementation of a cryptographically weak or outdated encryption algorithm for protecting sensitive credential data. The TranZman appliance's design likely predates current cryptographic best practices, or the developers chose a weaker algorithm for performance or compatibility reasons. CWE-327 categorizes this as the use of a broken or risky cryptographic algorithm, which is a common issue in legacy systems and appliances.

Attack Vector

The attack vector for this vulnerability is network-based. An attacker can exploit this weakness by:

1. Gaining network access to the TranZman appliance or intercepting network traffic
2. Obtaining encrypted credential data from the appliance's storage or communications
3. Applying cryptanalysis techniques appropriate to the weak algorithm in use
4. Reversing the encryption to recover plaintext credentials
5. Using the extracted credentials to access connected systems

The vulnerability does not require authentication or user interaction, making it exploitable by any attacker with network visibility to the target appliance. The weak cryptography can be reversed using readily available tools and techniques, lowering the barrier to exploitation.

Technical details and proof-of-concept information are available in the GitHub CVE Exploits Repository and the GitHub Gist Resource published by the security researcher.

Detection Methods for CVE-2025-63912

Indicators of Compromise

• Unusual network traffic patterns involving the TranZman appliance, particularly data exfiltration to external destinations
• Unauthorized access attempts to storage systems using credentials that should only be known to the TranZman appliance
• Evidence of credential harvesting tools or cryptanalysis utilities in network logs
• Authentication events from unexpected source IPs using TranZman-stored credentials

Detection Strategies

• Monitor network traffic to and from TranZman appliances for suspicious patterns or large data transfers
• Implement intrusion detection rules to identify attempts to access or extract encrypted credential stores
• Deploy endpoint detection solutions on systems that interact with the TranZman appliance to identify post-exploitation activity
• Review authentication logs on connected storage systems for anomalous access patterns

Monitoring Recommendations

• Enable detailed logging on the TranZman appliance and forward logs to a centralized SIEM for analysis
• Configure alerts for any administrative access to credential storage locations on the appliance
• Implement network segmentation to limit exposure of the TranZman appliance to untrusted networks
• Establish baselines for normal TranZman network activity to identify deviations that may indicate exploitation

How to Mitigate CVE-2025-63912

Immediate Actions Required

• Isolate affected Cohesity TranZman appliances from untrusted network segments immediately
• Rotate all credentials stored within or used by the TranZman appliance
• Review access logs on storage systems accessible via TranZman for signs of unauthorized access
• Implement network access controls to restrict connectivity to the appliance to only authorized systems
• Contact Cohesity support for guidance on available patches or firmware updates

Patch Information

At the time of publication, no vendor advisory or specific patch information has been released by Cohesity. Organizations should monitor Cohesity's security advisories and the GitHub CVE Exploits Repository for updates. Contact Cohesity support directly for the latest remediation guidance.

Workarounds

• Deploy the TranZman appliance on an isolated network segment with strict firewall rules
• Implement additional encryption layers (such as VPN tunnels) for all TranZman network communications
• Minimize the storage of long-term credentials on the appliance; use temporary credentials where possible
• Enable additional monitoring and alerting for any access to the appliance's configuration or credential stores
• Consider decommissioning affected appliances until a security patch is available, using alternative migration methods