1. Introduction
VMware vSphere Data Protection 6.x contains an information disclosure vulnerability. This means sensitive data could be revealed to unauthorised users. Systems running VMware vSphere Data Protection version 6.x are affected, potentially impacting the confidentiality of stored virtual machine data. A successful exploit may lead to loss of data integrity and availability.
2. Technical Explanation
The vulnerability in VMware vSphere Data Protection 6.x allows a local attacker to access sensitive information. This is due to insecure default configurations within the appliance. Exploitation requires local access to the affected system. The Common Vulnerabilities and Exposures (CVE) identifier for this issue is CVE-2018-3620.
- Root cause: Insecure default settings allow unauthorised access to data files.
- Exploit mechanism: An attacker with local access can read configuration or data files directly from the file system. For example, an attacker could use standard Linux commands like ‘cat’ or ‘less’ on sensitive files within the Data Protection appliance’s storage directories.
- Scope: VMware vSphere Data Protection 6.x is affected.
3. Detection and Assessment
You can confirm if a system is vulnerable by checking its version number. A thorough assessment involves reviewing file permissions on the data store.
- Quick checks: Use the VMware vSphere Data Protection appliance console to check the installed version.
- Scanning: Nessus plugin ID 118697 may detect this vulnerability, but results should be verified manually.
- Logs and evidence: Review system logs for unusual file access attempts or changes in permissions within the data store directories.
# Example command placeholder:
# vmware-vdp -version
4. Solution / Remediation Steps
Apply operating system mitigations as described by VMware. These steps aim to restrict access and protect sensitive data.
4.1 Preparation
- Ensure you have console access in case of issues. A roll back plan involves restoring from backup.
- A change window may be needed, depending on your environment and risk tolerance. Approval from the security team might be necessary.
4.2 Implementation
- Step 1: Implement the operating system mitigations described in VMware kb article VMSA-2018-0021.
- Step 2: Verify the changes have been applied correctly by checking file permissions and access controls on sensitive data directories.
4.3 Config or Code Example
Before
#Example - insecure permissions (may vary)
ls -l /var/vdp/data
-rw-r--r-- 1 root root 1024 Jan 1 00:00 sensitive_file.txt
After
#Example - secure permissions (may vary)
ls -l /var/vdp/data
-rw------- 1 root root 1024 Jan 1 00:00 sensitive_file.txt
4.4 Security Practices Relevant to This Vulnerability
Several security practices can help prevent this type of issue.
- Practice 1: Least privilege access reduces the impact if an attacker gains access. Limit user accounts with access to sensitive data stores.
- Practice 2: Regular patch cadence ensures systems are updated with the latest security fixes, mitigating known vulnerabilities.
4.5 Automation (Optional)
#Example - Bash script to restrict file permissions (use with caution)
#!/bin/bash
chmod 600 /var/vdp/data/*sensitive_file.txt #Replace *sensitive_file.txt with actual filenames
5. Verification / Validation
Confirm the fix by re-checking file permissions and attempting to access sensitive data as a non-privileged user.
- Post-fix check: Run ‘ls -l /var/vdp/data’ and confirm that sensitive files have restricted permissions (e.g., 600).
- Re-test: Attempt to read the contents of a sensitive file as a non-root user. Access should be denied.
- Smoke test: Verify that VMware vSphere Data Protection is still backing up and restoring virtual machines correctly.
- Monitoring: Monitor system logs for any attempts to access restricted files or directories.
# Post-fix command and expected output
ls -l /var/vdp/data
-rw------- 1 root root 1024 Jan 1 00:00 sensitive_file.txt
6. Preventive Measures and Monitoring
Update security baselines to include file permission requirements for VMware vSphere Data Protection.
- Baselines: Update your security baseline or policy to enforce strict file permissions on the data store directories, aligning with CIS benchmarks if applicable.
- Pipelines: Implement static analysis checks in your CI/CD pipeline to identify insecure default configurations during deployment.
- Asset and patch process: Review and apply VMware security advisories within 30 days of release.
7. Risks, Side Effects, and Roll Back
Incorrect file permission changes could disrupt backup operations.
- Risk or side effect 1: Incorrectly setting permissions may prevent the Data Protection appliance from accessing data files, causing backups to fail. Restore from backup if this occurs.
- Risk or side effect 2: Changes might require a restart of the VMware vSphere Data Protection service.
- Roll back:
- Restore file permissions to their original state using the backup created in step 4.1.
- Restart the VMware vSphere Data Protection service if necessary.
8. References and Resources
- Vendor advisory or bulletin: https://www.vmware.com/security/advisories/VMSA-2018-0021.html
- NVD or CVE entry: CVE-2018-3620
- Product or platform documentation relevant to the fix: VMware vSphere Data Protection 6.x Security Guide