CVE-2023-36013: Microsoft PowerShell Info Disclosure Flaw

CVE-2023-36013 Overview

CVE-2023-36013 is an information disclosure vulnerability affecting Microsoft PowerShell. This vulnerability allows an authenticated attacker with network access to potentially obtain sensitive information from affected systems. The vulnerability is classified under CWE-798 (Use of Hard-coded Credentials) and CWE-668 (Exposure of Resource to Wrong Sphere), indicating that the underlying issue involves improper handling of sensitive data or credentials within PowerShell.

Critical Impact

Authenticated attackers can leverage this vulnerability to access confidential information from affected PowerShell installations, potentially exposing sensitive data, credentials, or configuration details that could be used in further attacks.

Affected Products

• Microsoft PowerShell (multiple versions)

Discovery Timeline

• 2023-11-20 - CVE-2023-36013 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2023-36013

Vulnerability Analysis

This information disclosure vulnerability in Microsoft PowerShell enables authenticated attackers to extract sensitive information from target systems. The vulnerability stems from improper handling of sensitive data, with the associated CWE classifications pointing to issues with hard-coded credentials (CWE-798) and exposure of resources to wrong spheres (CWE-668).

The vulnerability requires network access and low-privilege authentication to exploit, meaning an attacker must have valid credentials to access the target system. Once authenticated, the attacker can leverage this flaw to read sensitive information that should normally be protected. The impact is limited to confidentiality, with no direct effect on system integrity or availability.

Root Cause

The root cause of CVE-2023-36013 relates to improper handling of sensitive data within PowerShell. The CWE classifications indicate two potential contributing factors:

1. CWE-798 (Use of Hard-coded Credentials): The software may contain hard-coded credentials that could be exposed or leveraged to access sensitive information.

2. CWE-668 (Exposure of Resource to Wrong Sphere): Sensitive resources may be exposed to actors outside their intended access scope, allowing unauthorized information retrieval.

Attack Vector

The attack vector for this vulnerability is network-based, requiring authenticated access to exploit. An attacker would need to:

1. Obtain valid low-privilege credentials for the target system
2. Establish network connectivity to the PowerShell environment
3. Execute commands or operations that trigger the information disclosure
4. Exfiltrate the exposed sensitive data for further analysis or attack planning

The vulnerability does not require user interaction and can be exploited without additional privileges beyond basic authentication. Microsoft has not disclosed specific exploitation techniques, but the information disclosed could potentially include credentials, configuration data, or other sensitive system information.

Detection Methods for CVE-2023-36013

Indicators of Compromise

• Unusual PowerShell script execution patterns from authenticated users
• Unexpected access to credential stores or sensitive configuration files
• Anomalous network traffic containing potentially leaked sensitive data
• Suspicious PowerShell cmdlet usage patterns attempting to enumerate system information

Detection Strategies

• Monitor PowerShell script block logging for suspicious commands targeting sensitive data
• Enable Module Logging and Transcription to capture PowerShell activity details
• Implement behavioral analysis to detect unusual PowerShell usage patterns
• Review Windows Event Logs for PowerShell events (Event IDs 4103, 4104, 4105, 4106)

Monitoring Recommendations

• Enable PowerShell script block logging via Group Policy
• Configure centralized log collection for PowerShell events
• Set up alerts for unusual PowerShell activity from low-privilege accounts
• Monitor for attempts to access credential stores or sensitive configuration data

How to Mitigate CVE-2023-36013

Immediate Actions Required

• Apply the latest Microsoft security updates for PowerShell immediately
• Review and audit PowerShell usage across the environment
• Implement least privilege access controls for PowerShell users
• Enable PowerShell Constrained Language Mode where possible

Patch Information

Microsoft has released security updates to address this vulnerability. Administrators should consult the Microsoft Security Update Guide for CVE-2023-36013 for detailed patch information and download links for affected PowerShell versions. Apply the appropriate security updates through Windows Update, Microsoft Update Catalog, or your organization's patch management system.

Workarounds

• Restrict PowerShell access to only users who require it for their roles
• Implement PowerShell Just Enough Administration (JEA) to limit capabilities
• Enable Constrained Language Mode to restrict potentially dangerous operations
• Monitor and audit all PowerShell activity until patches can be applied

# Enable PowerShell Script Block Logging via Registry
Set-ItemProperty -Path "HKLM:\SOFTWARE\Policies\Microsoft\Windows\PowerShell\ScriptBlockLogging" -Name "EnableScriptBlockLogging" -Value 1

# Enable Constrained Language Mode (example)
$ExecutionContext.SessionState.LanguageMode = "ConstrainedLanguage"