CVE-2022-31699: VMware Cloud Foundation Info Disclosure

CVE-2022-31699 Overview

CVE-2022-31699 is a heap-overflow vulnerability affecting VMware ESXi and VMware Cloud Foundation. This memory corruption flaw allows a malicious local actor with restricted privileges within a sandbox process to exploit improper memory handling and achieve partial information disclosure. The vulnerability stems from inadequate bounds checking when processing data in heap memory, enabling attackers who have already gained limited access to a sandboxed environment to read sensitive information they should not have access to.

Critical Impact

A local attacker with sandbox access can exploit this heap-overflow to leak sensitive memory contents, potentially exposing confidential data from the hypervisor environment.

Affected Products

• VMware ESXi versions 6.5, 6.7, and 7.0 (multiple patch levels)
• VMware Cloud Foundation versions 3.x (3.0 through 3.11)
• VMware Cloud Foundation versions 4.x (4.0 through 4.4.1.1)

Discovery Timeline

• 2022-12-13 - CVE-2022-31699 published to NVD
• 2025-04-22 - Last updated in NVD database

Technical Details for CVE-2022-31699

Vulnerability Analysis

This heap-overflow vulnerability (CWE-787: Out-of-bounds Write) occurs within VMware ESXi's sandbox process handling. The flaw enables an attacker who has already compromised a sandboxed process with restricted privileges to manipulate heap memory operations. When successfully exploited, the vulnerability allows the attacker to read memory contents beyond the intended buffer boundaries, resulting in partial information disclosure.

The exploitation requires local access and the attacker must already possess restricted privileges within a sandbox process. This limits the attack surface but creates a concerning scenario for multi-tenant environments where virtual machine isolation is critical. The partial information disclosure could expose hypervisor memory contents, potentially including configuration data, credentials, or information about other virtual machines running on the same host.

Root Cause

The root cause is improper bounds checking during heap memory operations within the ESXi sandbox process. When processing certain data structures, the code fails to properly validate the size or boundaries of heap allocations before performing write operations. This allows data to overflow beyond the allocated heap buffer, corrupting adjacent memory regions and enabling attackers to read unintended memory contents.

Attack Vector

The attack vector is local, requiring the attacker to have already established a foothold within a sandboxed process on the affected ESXi host. The exploitation flow involves:

1. Attacker gains initial access to a restricted sandbox process on the ESXi host
2. Attacker crafts malicious input that triggers the heap-overflow condition
3. The overflow corrupts adjacent heap memory structures
4. Attacker leverages the memory corruption to read memory contents beyond intended boundaries
5. Sensitive information is disclosed to the attacker

The vulnerability does not require user interaction and can be exploited with low complexity once the attacker has the necessary sandbox access.

Detection Methods for CVE-2022-31699

Indicators of Compromise

• Unusual memory access patterns or crashes within ESXi sandbox processes
• Unexpected heap allocation failures or corruption errors in ESXi logs
• Anomalous behavior from processes running with restricted sandbox privileges

Detection Strategies

• Monitor ESXi system logs for heap corruption errors or unexpected process crashes
• Implement memory integrity monitoring on ESXi hosts to detect heap overflow attempts
• Use VMware's health monitoring tools to identify abnormal sandbox process behavior
• Deploy host-based intrusion detection to monitor for privilege escalation attempts from sandbox processes

Monitoring Recommendations

• Enable verbose logging on ESXi hosts to capture heap-related errors
• Configure alerting for sandbox process anomalies in vCenter Server
• Monitor for unusual memory consumption patterns in ESXi processes
• Review audit logs for suspicious local access attempts to ESXi hosts

How to Mitigate CVE-2022-31699

Immediate Actions Required

• Apply VMware security patches as specified in VMware Security Advisory VMSA-2022-0030
• Restrict local access to ESXi hosts to only authorized administrators
• Review and audit accounts with access to sandbox processes on affected systems
• Implement network segmentation to limit access to ESXi management interfaces

Patch Information

VMware has released patches addressing this vulnerability. Administrators should consult the VMware Security Advisory VMSA-2022-0030 for specific patch versions and update instructions. Apply the appropriate patches for your ESXi version:

• ESXi 6.5: Apply the latest 6.5 security patch
• ESXi 6.7: Apply the latest 6.7 security patch
• ESXi 7.0: Apply the latest 7.0 security patch
• Cloud Foundation: Apply the appropriate Cloud Foundation bundle updates

Workarounds

• Limit local access to ESXi hosts by enforcing strict access controls and multi-factor authentication
• Minimize the number of accounts with access to sandbox processes
• Implement network-level controls to restrict management interface exposure
• Monitor and audit all local access to ESXi systems until patches can be applied

# Verify ESXi patch level
esxcli system version get

# Check installed VIBs for security patches
esxcli software vib list | grep -i patch

# Review local user access
esxcli system account list