1. Introduction
Accellion Secure File Transfer Appliance Detection indicates that an Accellion secure file transfer appliance is present on a network. These appliances are used for sharing sensitive data, but have been subject to high-profile vulnerabilities leading to potential data breaches. This affects organisations using the Accellion FTA product. A successful exploit could lead to confidentiality, integrity and availability compromise of stored files.
2. Technical Explanation
The detection identifies the web interface associated with Accellion Secure File Transfer. The appliance itself is not inherently vulnerable; however, its presence indicates a potential risk due to known vulnerabilities in older versions or unpatched systems. Attackers typically exploit weaknesses within the FTA software to gain unauthorised access to files stored on the appliance. Preconditions include network connectivity to the FTA instance and knowledge of its web interface URL.
- Root cause: The presence of a potentially vulnerable Accellion Secure File Transfer Appliance.
- Exploit mechanism: Attackers exploit known vulnerabilities in the Accellion software, such as those identified in 2021 (CVE-2021-26897 through CVE-2021-26899), to gain access to files.
- Scope: Systems running Accellion Secure File Transfer Appliance are affected.
3. Detection and Assessment
Confirming the presence of the appliance is the primary assessment step. This can be done through network scanning or direct inspection of web services.
- Quick checks: Access the suspected URL in a web browser to identify the Accellion login page.
- Scanning: Nessus vulnerability scan ID 163890 may detect the appliance. This is an example only, and other scanners may provide similar results.
- Logs and evidence: Web server logs may show access attempts to the FTA interface.
curl -I 4. Solution / Remediation Steps
The primary solution is to decommission or update the Accellion Secure File Transfer Appliance. If decommissioning, ensure data is migrated safely. If updating, follow Accellion’s official guidance.
4.1 Preparation
- Services: Stop the Accellion FTA service prior to decommissioning or patching.
- Dependencies: Identify any systems that rely on the FTA for file transfer and plan accordingly. Roll back involves restoring from backups if issues occur.
4.2 Implementation
- Step 1: Stop the Accellion Secure File Transfer Appliance service.
- Step 2: If decommissioning, securely erase all data from the appliance’s storage.
- Step 3: If patching, download and install the latest version of Accellion FTA following official documentation.
4.3 Config or Code Example
This vulnerability does not involve specific configuration changes; it relates to the presence of a vulnerable system.
4.4 Security Practices Relevant to This Vulnerability
Several security practices can help mitigate risks associated with this type of vulnerability.
- Least privilege: Limit access to sensitive data and systems, reducing the impact if compromised.
- Asset inventory: Maintain a complete inventory of all assets on the network to identify vulnerable systems quickly.
- Patch management: Implement a regular patch management process to ensure systems are up-to-date with security fixes.
4.5 Automation (Optional)
Automation is not directly applicable for this detection, as it focuses on identifying the presence of an appliance rather than applying a fix. However, automated scanning can help identify FTA instances on the network.
5. Verification / Validation
Verify that the Accellion Secure File Transfer Appliance has been decommissioned or updated to a secure version.
- Post-fix check: Attempt to access the FTA web interface; it should no longer be accessible if decommissioned, or show the latest version information if patched.
- Re-test: Re-run the initial network scan to confirm the appliance is no longer detected.
curl -I 6. Preventive Measures and Monitoring
Regular asset discovery and vulnerability scanning are key preventive measures.
- Baselines: Update security baselines to include known vulnerable software, such as older versions of Accellion FTA.
- Pipelines: Integrate vulnerability scanning into CI/CD pipelines to identify potential issues early in the development lifecycle.
- Asset and patch process: Implement a regular asset discovery and patch management cycle to ensure all systems are up-to-date with security fixes.
7. Risks, Side Effects, and Roll Back
Decommissioning may disrupt file transfer workflows. Patching could introduce compatibility issues.
- Risk or side effect 1: Service disruption during decommissioning. Mitigation: Plan downtime carefully and communicate with stakeholders.
- Roll back: Restore from backups if decommissioning fails, or revert to the previous version of Accellion FTA if patching causes issues.
8. References and Resources
Official advisories are the best source of information for this vulnerability.
- Vendor advisory or bulletin: https://www.accellion.com/security-bulletins
- NVD or CVE entry: Search NVD for Accellion vulnerabilities (e.g., CVE-2021-26897).