Bluetooth HCI Adaptor Realtek Vulnerability Let Attackers Delete Arbitrary Files

A high-severity vulnerability has been discovered in Realtek’s Bluetooth HCI Adaptor that allows local attackers to delete arbitrary files and potentially escalate privileges on affected systems. 

The vulnerability, tracked as CVE-2024-11857, was published to the GitHub Advisory Database just three hours ago and represents a significant security risk for systems utilizing Realtek Bluetooth hardware components.

Overview of Bluetooth HCI Adaptor vulnerability

The newly disclosed vulnerability stems from a Link Following weakness classified under CWE-59 in the Common Weakness Enumeration database. 

This flaw enables local attackers with regular user privileges to exploit the Bluetooth HCI Adaptor’s file handling mechanisms through symbolic link manipulation. 

The attack vector requires minimal complexity and no user interaction, making it particularly concerning for security professionals.

The exploitation process involves attackers creating a symbolic link with an identical name to a specific file that the Bluetooth HCI Adaptor expects to process. 

When the adaptor attempts to access the legitimate file, it inadvertently follows the malicious symbolic link, resulting in the deletion of arbitrary files pointed to by the attacker-controlled link. 

This mechanism bypasses normal file system protections, allowing unauthorized file manipulation beyond the attacker’s typical privilege level.

The vulnerability affects the Bluetooth Host Controller Interface (HCI) layer, which serves as the standardized interface between the Bluetooth controller and the host system. 

This critical position in the Bluetooth stack amplifies the potential impact, as the HCI layer handles low-level Bluetooth operations and maintains elevated system access for hardware communication.

Security researchers have assigned CVE-2024-11857 a high severity rating reflecting its significant potential for system compromise. 

Risk Factors	Details
Affected Products	Realtek Bluetooth HCI Adaptor (specific firmware versions unspecified)
Impact	Arbitrary file deletion
Exploit Prerequisites	– Local system access- Low-privilege user account- No user interaction required
CVSS Score	8.5 (High)

Mitigation Strategies

Organizations utilizing Realtek Bluetooth hardware should immediately assess their exposure to this vulnerability. 

The GitHub Advisory indicates that affected versions and patched versions remain “Unknown,” suggesting that comprehensive vendor guidance is still pending. 

This uncertainty necessitates proactive defensive measures until official patches become available.

According to the Report, System administrators should implement the principle of least privilege policies more strictly, limiting user access to critical system directories and files. 

Additionally, monitoring tools should be configured to detect unusual symbolic link creation patterns, particularly those targeting system files or Bluetooth-related components.

Network segmentation and endpoint detection solutions can help identify and contain potential exploitation attempts. 

Organizations should also consider temporarily disabling non-essential Bluetooth functionality on critical systems until vendor patches are released and thoroughly tested.

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