CWE-1190: DMA Device Enabled Too Early in Boot Phase

What is DMA Device Enabled Too Early in Boot Phase?

• Overview: This vulnerability occurs when a Direct Memory Access (DMA) capable device is activated too early in the boot process before security settings are established, potentially allowing unauthorized access to system memory and data.

• Exploitation Methods:

• Attackers can exploit this by using the DMA device to access or modify data directly in memory.
• Common techniques include leveraging untrusted devices that are activated during early boot to bypass operating system controls and extract sensitive information.

• Security Impact:

• Direct consequences include unauthorized data access and privilege escalation.
• Potential cascading effects include compromised system integrity and exposure of sensitive information across the system.
• Business impact can involve data breaches, loss of customer trust, regulatory penalties, and financial losses.

• Prevention Guidelines:

• Ensure DMA devices are only enabled after security configurations are in place during boot.
• Implement strict access controls and trust levels for devices activated during early boot.
• Use virtualization-based mitigations such as Input-Output Memory Management Units (IOMMUs) to restrict DMA access.
• Regularly update firmware and software to patch known vulnerabilities.
• Monitor and audit device activities to detect and respond to potential unauthorized access promptly.

Corgea can automatically detect and fix DMA Device Enabled Too Early in Boot Phase in your codebase. Try Corgea free today.

Technical Details

Likelihood of Exploit: Not specified

Affected Languages: Not Language-Specific

Affected Technologies: System on Chip

Vulnerable Code Example

class BootManager:
    def __init__(self):
        self.dma_device_enabled = False
        self.security_configured = False

    def enable_dma_device(self):
        # Vulnerable: Enabling DMA device before security configurations are applied
        self.dma_device_enabled = True
        print("DMA device enabled.")

    def configure_security(self):
        # Placeholder for security configuration logic
        self.security_configured = True
        print("Security configured.")

    def boot_system(self):
        # Vulnerable sequence: DMA device is enabled before security is configured
        self.enable_dma_device()
        self.configure_security()
        print("System boot complete.")

boot_manager = BootManager()
boot_manager.boot_system()

Explanation:

In this vulnerable example, the enable_dma_device method is called before the configure_security method during the boot process. This sequence means the DMA device is enabled before the system's security configurations are established, potentially allowing an attacker to exploit the system's memory or gain unauthorized access.

How to fix DMA Device Enabled Too Early in Boot Phase?

To fix this vulnerability, ensure that the system's security configurations are applied before enabling any DMA-capable devices. The boot sequence should be modified to first establish all necessary security measures before enabling the DMA device. This reordering mitigates the risk of unauthorized access through the DMA path before the system is secured.

Fixed Code Example

class BootManager:
    def __init__(self):
        self.dma_device_enabled = False
        self.security_configured = False

    def enable_dma_device(self):
        # Ensure security configurations are applied before enabling DMA
        if not self.security_configured:
            raise Exception("Security not configured. Cannot enable DMA device.")
        self.dma_device_enabled = True
        print("DMA device enabled.")

    def configure_security(self):
        # Implement security configuration logic here
        self.security_configured = True
        print("Security configured.")

    def boot_system(self):
        # Fixed sequence: Security is configured before enabling DMA device
        self.configure_security()
        self.enable_dma_device()
        print("System boot complete.")

boot_manager = BootManager()
boot_manager.boot_system()

Key Fixes:

• Check Security Configuration: Before enabling the DMA device, check if the security configurations have been applied. If not, raise an exception to prevent the DMA device from being enabled prematurely.
• Reorder Boot Sequence: Call configure_security before enable_dma_device during the boot process to ensure security configurations are in place prior to enabling DMA devices. This reordering ensures that the system is secured before any DMA operations are possible.