CVE-2015-0016
Microsoft Windows TS WebProxy Directory Traversal Vulnerability
Executive Summary
CVE-2015-0016 is a critical severity vulnerability affecting appsec. It is classified as an undisclosed flaw. This vulnerability is actively being exploited in the wild.
Precogs AI Insight
"This exposure is a direct consequence of within Directory traversal vulnerability, allowing the absence of comprehensive security boundaries. If successfully exploited, a malicious user could escalate their own privileges to administrative levels without proper credentials. Precogs AI Analysis Engine utilizes semantic code analysis to neutralize the threat at the source level."
What is this vulnerability?
CVE-2015-0016 is categorized as a critical Path Traversal flaw. Based on our vulnerability intelligence, this issue occurs when the application fails to securely handle untrusted data boundaries.
Directory traversal vulnerability in the TS WebProxy (TSWbPrxy) component in Microsoft Windows allows remote attackers to escalate privileges..
This architectural defect enables adversaries to bypass intended security controls, directly manipulating the application's execution state or data layer. Immediate strategic intervention is required.
Risk Assessment
| Metric | Value |
|---|---|
| CVSS Base Score | 9.8 (CRITICAL) |
| Vector String | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H |
| Published | May 25, 2022 |
| Last Modified | May 25, 2022 |
| Related CWEs | N/A |
Impact on Systems
✅ Sensitive File Disclosure: Unauthorized access to critical configuration files (/etc/passwd, .env files, private SSH keys).
✅ Application Source Leak: Attackers can download proprietary source code and hardcoded credentials.
✅ Remote Code Execution: By combining with log poisoning, attackers can write PHP/JSP shells into web-accessible directories.
How to fix this issue?
Implement the following strategic mitigations immediately to eliminate the attack surface.
1. Indirect References Avoid using direct file paths. Utilize indirect references (like database IDs) mapped to backend files.
2. Strict Path Resolution If direct paths are required, resolve the absolute path and rigorously verify the path starts with the expected base directory using native OS path resolving functions.
3. Chroot Jails Confine the application processes to highly restricted directory structures (chroot) with minimum readable boundaries.
Vulnerability Signature
// Vulnerable File Access
import os
def get_image(request):
filename = request.GET.get('file')
# VULNERABLE: No validation preventing moving upwards in the directory tree
filepath = os.path.join('/var/www/images/', filename)
return open(filepath, 'rb').read()
// EXPLOIT PAYLOAD: ?file=../../../../../../../../etc/passwd
References and Sources
Vulnerability Code Signature
Attack Data Flow
| Stage | Detail |
|---|---|
| Source | Untrusted User Input |
| Vector | Input flows through the application logic without sanitization |
| Sink | Execution or Rendering Sink |
| Impact | Application compromise, Logic Bypass, Data Exfiltration |
Vulnerable Code Pattern
# ❌ VULNERABLE: Unsanitized Input Flow
def process_request(request):
user_input = request.GET.get('data')
# Taint sink: processing untrusted data
execute_logic(user_input)
return {"status": "success"}
Secure Code Pattern
# ✅ SECURE: Input Validation & Sanitization
def process_request(request):
user_input = request.GET.get('data')
# Sanitized boundary check
if not is_valid_format(user_input):
raise ValueError("Invalid input format")
sanitized_data = sanitize(user_input)
execute_logic(sanitized_data)
return {"status": "success"}
How Precogs Detects This
Precogs AI Analysis Engine maps untrusted input directly to execution sinks to catch complex application security vulnerabilities.\n