What Happened Millions of AMD Chips?

At the DEFCON hacker conference, researchers Enrique Nissim and Krzysztof Okupski unveiled a severe vulnerability in AMD chips, dubbed “Sinkclose.” This flaw, which affects AMD processors dating back to 2006, permits attackers to execute malicious code within the highly privileged System Management Mode (SMM) of the processor. This mode is typically reserved for crucial firmware operations, making any compromise especially dangerous.

The Sinkclose vulnerability could let malware hide deeply in a system, making it nearly impossible to detect or remove, potentially requiring users to discard their computers. The flaw exploits a feature called TClose, which is supposed to ensure compatibility with older devices but can be manipulated to gain unauthorized access to protected memory.

Unfixable Sinkclose Flaw – Technically What Happened

The Sinkclose flaw leverages a feature in AMD chips called TClose, designed to maintain compatibility with older devices. By exploiting this feature, attackers can trick the SMM code into executing malicious instructions at root, effectively gaining control at the highest privilege level. This kind of attack could lead to the installation of nearly undetectable and virtually unfixable infections of malware, known as a “bootkit,” which survives even after the operating system is reinstalled.

AMD Response to Hundreds of Millions of AMD Chips

AMD has acknowledged the open flaw in hundreds of millions of AMD chips allows this believed virtually unfixable to infection threats and released mitigation options for their EPYC datacenter products and Ryzen PC products, with further mitigations for embedded products to follow. 

Affected AMD Chip Types to Sinkclose Vulnerability

AMD has acknowledged the issue and released mitigations for its EPYC and Ryzen processors, with further updates planned for embedded systems. However, the flaw requires kernel-level access to exploit, which sophisticated hackers might already have. The researchers are concerned that, despite the complexity of the exploit, its deep level of control makes it crucial for users to apply patches as soon as they are available.

Below is a table indicating the types of AMD chips affected by the Sinkclose flaw:

Note: AMD security bulletin page listing chips affected by Sinkclose.

Criticality Score of a Virtually Unfixable AMD Chip Flaw to Infections

• Criticality Level: 9/10
• This flaw is rated extremely high due to its potential to grant attackers persistent, undetectable access to a system’s core functions, making this access to the privileged portions of a computer a significant threat to businesses, governments, and individual users.

Why this New “Sinkclose Flaw” Matters

The Sinkclose flaw’s impact is far-reaching, affecting both consumer-grade PCs and enterprise-level servers. The ability to persist through system reboots and even operating system reinstalls makes this flaw particularly dangerous. For organizations relying on AMD processors, this vulnerability could mean a complete loss of control over their IT infrastructure, with significant implications for data security and operational continuity.

What Can You Do Now

• For Enterprises: Assess the extent of AMD processor usage within your infrastructure and apply any available patches immediately.
• For Consumers: Stay updated with your PC manufacturer’s firmware updates and apply them as soon as they’re available. Consider contacting your manufacturer for specific guidance on your system.
• Consider Changing Vendors: If your business heavily relies on AMD processors and cannot afford the risk, it might be prudent to explore alternative processor vendors.
• Leverage ZeroTrust “Out-of-the-Box”: Look to onboard Warden as quickly as possible to put in place a mechanism designed from the ground up to stop any malicious code, known or unknown from being able to attack your systems.

Mitigation Strategies

• Firmware Updates: Regularly check for and apply firmware updates from your system or motherboard manufacturer.
• Enhanced Monitoring: Implement advanced monitoring solutions that can detect unusual activity within System Management Mode.
• Hardware-Based Security: Consider using hardware-based security solutions that provide additional protection against such low-level attacks.
• Onboard MSP with ZeroTrust: Warden Vault not only can protect your endpoints, network and cloud systems with a professional team 24x7x365.

Strategic Truths

• Depth of Compromise: The ability for malware to persist at such a low level in the system architecture is a stark reminder of the critical importance of firmware security and having a ZeroTrust Cybersecurity architecture in place as well to prevent any future exploits from working against your systems.
• Long-Term Implications: Given the widespread use of AMD chips, the long-term implications of Sinkclose could involve a fundamental reassessment of processor security across the industry. We also believe it continues to validate that detection solutions such as anti-virus can not detect nor stop this threat. Reinforces the need to transition sooner rather than later to a ZeroTrust solution such as Warden.
• Review our understanding of Risk: In cybersecurity, we seldom talk about reviewing the fundamental causes of risk. Warden addresses risk from a different viewpoint that through the traditional approach of focusing on trying to prevent the delivery of malicious payloads. Its time we do, so below is a quick understanding why using Warden’s ZeroTrust approach changes the battleground.

Delivery Mechanism vs. Payload Protection: Understanding the True Cybersecurity Battleground

In cybersecurity, traditional defenses focus on preventing malicious payloads from entering systems, addressing stages like Reconnaissance, Weaponization, Delivery, and Exploitation. However, as attackers evolve, these methods can fall short. This is where Warden’s approach shines. Instead of just blocking payload delivery, Warden ensures robust security even after a payload has entered the system using patented Kernel Level API Virtualization and Kernel Level Attack Surface Reduction (KLASR) developed by Xcitium and is the main reason its the core of Warden.

Traditional Approach: Blocking Delivery Mechanisms

Cybersecurity efforts traditionally focus on:

1. Reconnaissance: Monitoring and gathering intelligence to identify threats.
2. Weaponization: Detecting and mitigating malicious payload creation.
3. Delivery: Blocking phishing emails and malicious links.
4. Exploitation: Patching vulnerabilities and deploying intrusion detection systems.

These measures are essential but not foolproof, as sophisticated attackers can bypass them.

Warden’s Approach: Protecting Against Payloads

Warden’s strategy emphasizes securing systems even after a payload’s delivery through:

1. Kernel Level API Virtualization: Warden’s technology creates a virtualized environment at the kernel level, isolating the OS from untrusted applications, thereby neutralizing malicious payloads.
2. Kernel Level Attack Surface Reduction (KLASR): KLASR introduces a virtualization layer between processes and Kernel functions, minimizing vulnerabilities by virtualizing essential components like File System, Registry, Kernel Object, Service, and DCOM/RPC. Thus, minimizing the attack surface where these are vulnerable to attack.

Why Warden’s Approach is Superior

1. Resilience Against Unknown Threats: Warden’s approach protects against both known and unknown threats by isolating them from critical system components, unlike traditional methods that rely on patching known vulnerabilities.
2. Comprehensive Protection: It ensures protection even if initial defenses fail, providing a layered security strategy.
3. Reduced Dependency on Updates: By reducing the need for constant updates and patches, Warden offers a more stable and secure environment.

In essence, while preventing payload delivery is crucial, ensuring ongoing protection against malicious payloads is vital. Warden’s innovative use of Kernel Level API Virtualization and KLASR offers a robust defense against the evolving threat landscape.

Summary Wrap Up

The discovery of the Sinkclose flaw in AMD processors represents a significant threat to cybersecurity, particularly due to its ability to embed itself at the deepest levels of a computer’s operation. Organizations and individuals using AMD processors should act swiftly to apply any available patches and consider additional security measures to protect their systems. The vulnerability highlights the ongoing need for vigilance in firmware security, as the consequences of such flaws can be catastrophic.

Thus, the Sinkclose vulnerability in the AMD processors underscores a critical security risk with far-reaching implications. Exploiting this flaw can grant attackers persistent, undetectable access to system core functions, making it essential for users to apply patches and reassess their security strategies. Adopting a ZeroTrust approach with solutions like Warden can provide robust protection against such sophisticated threats, ensuring resilience even when traditional defenses fall short.