CVE-2023-1314
📋 TL;DR
A local privilege escalation vulnerability in cloudflared's Windows 32-bit installer allows attackers without administrative rights to delete or replace system files via symbolic link manipulation. This affects only the installer for cloudflared on 32-bit Windows devices, not the cloudflared client itself. Attackers need local access to exploit this vulnerability.
💻 Affected Systems
- cloudflared Windows installer
📦 What is this software?
Cloudflared by Cloudflare
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise through deletion of critical system files or replacement with malicious files, potentially leading to persistent access or system instability.
Likely Case
Local attackers delete specific files to disrupt system functionality or replace files to gain elevated privileges.
If Mitigated
Limited impact if proper access controls prevent unauthorized local access or if the vulnerable installer is not present.
🎯 Exploit Status
Exploitation requires local access and knowledge of symbolic link creation. The technique is well-documented for MSI installer vulnerabilities.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2023.3.1 and later
Vendor Advisory: https://github.com/cloudflare/cloudflared/security/advisories/GHSA-7mjv-x3jf-545x
Restart Required: No
Instructions:
1. Download the latest cloudflared installer from https://github.com/cloudflare/cloudflared/releases. 2. Uninstall any existing vulnerable version. 3. Install the updated version. 4. Remove any old installer files from the system.
🔧 Temporary Workarounds
Remove vulnerable installer
windowsDelete the vulnerable MSI installer files from world-writable directories to prevent exploitation.
Remove cloudflared installer files (typically .msi) from C:\Windows\Temp and other writable directories
Restrict local access
allImplement strict access controls to prevent unauthorized local access to affected systems.
🧯 If You Can't Patch
- Remove the vulnerable cloudflared installer files from all world-writable directories
- Implement strict file system permissions to prevent symbolic link creation in sensitive directories
🔍 How to Verify
Check if Vulnerable:
Check if cloudflared installer version 2023.3.0 or earlier exists on Windows 32-bit systems, particularly in world-writable directories.Check Version:
Check installer file properties or registry entries for cloudflared version informationVerify Fix Applied:
Verify cloudflared installer version is 2023.3.1 or later and no vulnerable installer files remain on the system.📡 Detection & Monitoring
Log Indicators:
- Unusual file deletion events in system logs
- MSI installer repair process triggered unexpectedly
Network Indicators:
- No network indicators - this is a local attack
SIEM Query:
Search for event IDs related to MSI installer activity or file deletion in sensitive directories