🛡️ Critical VMware Tools VGAuth Vulnerabilities Enable Full System Access for Attackers

Published on: July 26, 2025

By: CyberDudeBivash Editorial Team

Website:cyberdudebivash.com

⚠️ The Issue: Privilege Escalation in VMware Tools VGAuth

Two serious vulnerabilities in the VGAuth (Guest Authentication Service) component of VMware Tools for Windows can allow a local attacker to escalate any low-privilege user account to full SYSTEM-level access within Windows virtual machines.These vulnerabilities—CVE‑2025‑22230 (high severity) and CVE‑2025‑22247 (moderate severity)—impact VMware Tools versions prior to 12.5.1/12.5.2 on both ESXi-hosted guests and standalone VMware Workstation deployments.Cyber Security News+6Cyber Security News+6LinkedIn+6

🔧 Vulnerabilities Explained

🔐 CVE‑2025‑22230: Named Pipe Hijacking (Authentication Bypass)

VGAuth creates named pipes using predictable naming patterns (\\.\pipe\vgauth-service-<username>) without the FILE_FLAG_FIRST_PIPE_INSTANCE flag, allowing attackers to pre-create malicious pipes. When the service later authenticates SYSTEM via that pipe, it unwittingly grants superuser privileges.Cyber Security News

🗂 CVE‑2025‑22247: Path Traversal via Alias Store Management

VGAuth's alias management operations do not sanitize username inputs, allowing malicious path traversal (e.g. ../../evil) via symlinks and symbolic junctions. This enables attackers to redirect file operations to system directories and hijack DLLs for SYSTEM-level code execution.Cyber Security News

📊 Vulnerability Summary

🚨 Why It Matters

• Complete System Control from low-privilege guest accounts.
• Potential lateral movement within virtualized environments.
• Attackers can extract SAML tokens, certificates, or manipulate guest operations.
• Dangerous in multi-tenant and corporate VM setups.

🛡️ What You Should Do Now

1. Immediately upgrade VMware Tools to version 12.5.2 or newer on all Windows guest VM environments.
2. Verify patch deployment across your VMware Estate (both Workstation and ESXi-hosted VMs).
3. Audit VGAuth usage—disable guest alias features if not required.
4. Monitor for suspicious VGAuth activity and anomalies in named pipes or alias management logs.
5. Integrate privileged escalation detection for VM internal behavior.

🧠 Expert Insight

“These issues expose a core vulnerability in VM guest-host bridging—VGAuth is an enclave of trust, and attackers exploit its predictable structure. Administrators must treat it as high-risk.”
— Positive Technologies / PT SWARM researcher Sergey BliznyukCCB Safeonweb+4GBHackers+4Facebook+4Cyber Security NewsFacebook+7Cyber Security News+7Cyber Security News+7cisa.gov

🧰 Broader Takeaways

• Guest-side tools can introduce serious escalation risks even when hypervisor isolation is intact.
• Predictable system behavior (e.g. pipe names, file paths) is an easy exploitation path.
• Regular patching and runtime audits are vital, not optional—especially in multi-tenant virtual environments.

✅ Key Takeaways

• Two vulnerabilities (CVE‑2025‑22230 & CVE‑2025‑22247) in VGAuth allow SYSTEM-level access.
• VMware has released updates in VMware Tools v12.5.1 and v12.5.2 to address these flaws.
• Immediate upgrade, security audits, and proactive escalation monitoring are essential.

💬 Let’s Discuss

• Are you using VMware Tools in your Windows guest infrastructure?
• Have you audited VGAuth access or pipe usage logs?
• What tools do you use for privilege escalation detection within VMs?

Share your approach or questions in the comments or connect with us at @CyberDudeBivash.

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Tags: #VMwareTools #VGAuth #PrivilegeEscalation #VirtualizationSecurity #CVE202522230 #CVE202522247 #Cybersecurity #ContainerSecurity #CyberDudeBivash