CVE-2023-5097

Executive Summary

CVE-2023-5097 is a path traversal vulnerability in HYPR Workforce Access on Windows, affecting versions before 8.7. The vulnerability stems from improper input validation, allowing an authenticated local attacker to traverse directories and potentially read or write arbitrary files on the system. With a CVSS score of 7.0, this vulnerability poses a significant risk to confidentiality and integrity, though it requires local access. No public proof-of-concept (PoC) or exploit code has been released, and the patch status remains unknown. This report provides a comprehensive analysis, including detection rules, exploitation scenarios, and remediation guidance.

Supply Chain & Package Security

HYPR Workforce Access is a proprietary enterprise solution, not distributed via public package registries like NPM or PyPI. Therefore, supply chain risks are limited to the vendor's distribution channels. Organizations should verify the integrity of HYPR binaries through official vendor checksums and ensure they are obtained from trusted sources.

CVSS Breakdown & Threat Level

• CVSS Score: 7.0 (High)
• Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
• Attack Vector: Local (AV:L) – Requires physical or remote access to the system.
• Attack Complexity: Low (AC:L) – No special conditions required.
• Privileges Required: Low (PR:L) – Attacker needs valid credentials.
• User Interaction: None (UI:N) – No user action needed.
• Scope: Unchanged (S:U) – Vulnerability affects only the vulnerable component.
• Confidentiality Impact: High (C:H) – Potential for full file read.
• Integrity Impact: High (I:H) – Potential for file modification.
• Availability Impact: High (A:H) – Potential for system disruption.

Threat Level: High. While local access is required, the low complexity and high impact make this a serious threat for enterprise environments where attackers may have footholds.

Deep Dive & Mechanics

The vulnerability exists in the HYPR Workforce Access client for Windows, specifically in how it handles file paths during input validation. The application fails to properly sanitize user-supplied input used in file operations, allowing an attacker to inject path traversal sequences (e.g., ../) to escape the intended directory.

Root Cause: The application does not validate or canonicalize file paths before using them in file system operations. This allows an attacker to specify paths like ../../windows/system32/config/sam to access sensitive files outside the application's sandbox.

Attack Vector: An authenticated local user can exploit this by crafting a malicious request to the HYPR service, which then processes the path without proper validation. The attacker could read configuration files, user data, or even write malicious files to escalate privileges.

Impact: Successful exploitation could lead to:

• Unauthorized read of sensitive files (e.g., credentials, configuration).
• Unauthorized write of files, potentially leading to code execution.
• Denial of service by overwriting critical system files.

Vulnerable vs. Patched Code

Since the patch is unknown, we can infer the fix based on common path traversal mitigations.

Vulnerable Code (Hypothetical):

string userInput = GetUserInput();
string filePath = Path.Combine(baseDirectory, userInput);
string content = File.ReadAllText(filePath);

Patched Code (Hypothetical):

string userInput = GetUserInput();
string fullPath = Path.GetFullPath(Path.Combine(baseDirectory, userInput));
if (!fullPath.StartsWith(baseDirectory, StringComparison.OrdinalIgnoreCase))
{
    throw new SecurityException("Invalid path.");
}
string content = File.ReadAllText(fullPath);

The patched version uses Path.GetFullPath to canonicalize the path and then checks that it starts with the intended base directory, preventing traversal.

Exploitation & Lab Setup

Red Team

Lab Setup:

1. Install HYPR Workforce Access version 8.6 on a Windows 10/11 VM.
2. Create a local user account with low privileges.
3. Identify the HYPR service endpoint (e.g., named pipe or local HTTP).

Exploitation Steps:

1. Log in as the low-privileged user.
2. Send a crafted request to the HYPR service with a path traversal payload:

   GET /api/files?path=../../windows/system32/config/sam HTTP/1.1
   Host: localhost
   

3. If successful, the response will contain the contents of the SAM file.

Note: No public exploit code exists; this is a hypothetical scenario.

Blue Team

Detection:

• Monitor for file access patterns that include .. sequences in HYPR-related processes.
• Use Sysmon to log process creation and file access events.
• Enable Windows Event Logging for file system audits.

Hunting:

• Search for HYPR process (e.g., HYPRService.exe) accessing files outside its installation directory.
• Look for Event ID 4663 (File accessed) with paths containing ...

Indicators of Compromise (IOCs)

• File Paths: C:\Program Files\HYPR\* with traversal patterns.
• Process: HYPRService.exe accessing C:\Windows\System32\* or other sensitive paths.
• Network: Local connections to HYPR service endpoints with suspicious path parameters.
• Registry: Unusual modifications to HYPR configuration keys.

Detection Engineering

YARA Rule

rule CVE_2023_5097_HYPR_Path_Traversal {
    meta:
        description = "Detects path traversal attempts in HYPR Workforce Access logs"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2023-5097"
    strings:
        $traversal = /\.\.\/|\.\.\\/
        $hypr_path = /HYPR/i
    condition:
        $hypr_path and $traversal
}

Sigma Rule

title: CVE-2023-5097 HYPR Path Traversal Attempt
id: 8a4b3c2d-1e5f-4a6b-8c7d-9e0f1a2b3c4d
status: experimental
description: Detects path traversal patterns in HYPR Workforce Access logs
author: Valters IT
date: 2025-04-10
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith: '\HYPRService.exe'
        CommandLine|contains: '..'
    condition: selection
falsepositives:
    - Legitimate use of relative paths in HYPR configuration
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2023-5097 HYPR Path Traversal Attempt"; flow:to_server; content:".."; http_uri; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Upgrade: Update HYPR Workforce Access to version 8.7 or later if available. Contact HYPR support for patch details.
2. Restrict Access: Limit local user permissions on systems running HYPR.
3. Monitor: Implement the detection rules above to identify exploitation attempts.

Long-Term Measures:

• Apply the principle of least privilege to all user accounts.
• Use application whitelisting to prevent unauthorized executables.
• Regularly audit file system access logs for anomalies.

Workarounds:

• If patching is not possible, disable the vulnerable feature or restrict access to the HYPR service via firewall rules.

Report generated by Valters IT DevSecOps Intelligence Unit.