CVE-2021-22914
📋 TL;DR
CVE-2021-22914 is an information disclosure vulnerability in Citrix Cloud Connector where sensitive authentication parameters are stored in plaintext in installation log files. This affects organizations using command-line installation with secure parameters, potentially allowing attackers to obtain credentials and access Citrix Cloud environments. Only installations using command-line parameters are vulnerable, not interactive or parameter file installations.
💻 Affected Systems
- Citrix Cloud Connector
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers obtain administrative credentials from log files, gain full access to Citrix Cloud environment, and compromise all managed resources and data.
Likely Case
Attackers with local or network access to log files extract credentials and gain unauthorized access to Citrix Cloud management functions.
If Mitigated
With proper access controls and monitoring, attackers cannot access log files or the extracted credentials are no longer valid.
🎯 Exploit Status
Exploitation requires access to installation log files, which typically requires some level of system access. The vulnerability is simple to exploit once log files are accessed.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 6.31.0.62192 and later
Vendor Advisory: https://support.citrix.com/article/CTX316690
Restart Required: Yes
Instructions:
1. Download Citrix Cloud Connector version 6.31.0.62192 or later from Citrix. 2. Run the installer with administrative privileges. 3. Follow the installation wizard. 4. Restart the system after installation completes.
🔧 Temporary Workarounds
Secure or Delete Installation Logs
windowsRemove or secure installation log files that may contain sensitive parameters
Remove-Item -Path "C:\ProgramData\Citrix\WorkspaceCloud\Logs\*.log" -Force
Remove-Item -Path "C:\ProgramData\Citrix\WorkspaceCloud\InstallLogs\*.log" -Force
Restrict Access to Log Directories
windowsSet strict permissions on log directories to prevent unauthorized access
icacls "C:\ProgramData\Citrix\WorkspaceCloud\Logs" /inheritance:r /grant:r "SYSTEM:(OI)(CI)F" "Administrators:(OI)(CI)F"
icacls "C:\ProgramData\Citrix\WorkspaceCloud\InstallLogs" /inheritance:r /grant:r "SYSTEM:(OI)(CI)F" "Administrators:(OI)(CI)F"
🧯 If You Can't Patch
- Rotate all Citrix Cloud credentials that were used during vulnerable installations
- Implement strict access controls and monitoring for log file directories
🔍 How to Verify
Check if Vulnerable:
Check installation method: If installed via command line with parameters (not parameter file) and version is below 6.31.0.62192, check for sensitive data in installation logs.Check Version:
Get-ItemProperty -Path "HKLM:\SOFTWARE\Citrix\WorkspaceCloud\Connector" -Name "Version" | Select-Object -ExpandProperty VersionVerify Fix Applied:
Verify Citrix Cloud Connector version is 6.31.0.62192 or higher and check that new installations do not store sensitive data in logs.📡 Detection & Monitoring
Log Indicators:
- Unauthorized access attempts to log file directories
- Patterns of credential extraction from log files
- Multiple failed authentication attempts followed by successful access
Network Indicators:
- Unusual API calls to Citrix Cloud from unexpected sources
- Traffic patterns indicating credential harvesting
SIEM Query:
EventID=4663 AND ObjectName LIKE '%Citrix%WorkspaceCloud%Logs%' AND AccessMask='0x10000'