CVE-2020-11256 in Snapdragon Wired Infrastructure and Networking
Summary
by MITRE • 06/09/2021
Memory corruption due to lack of check of validation of pointer to buffer passed to trustzone in Snapdragon Wired Infrastructure and Networking
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Analysis
by VulDB Data Team • 06/11/2021
The vulnerability identified as CVE-2020-11256 represents a critical memory corruption issue affecting Qualcomm Snapdragon chipsets within the realm of wired infrastructure and networking components. This flaw resides in the TrustZone security subsystem where improper validation of buffer pointers leads to potential memory corruption during processing of network traffic. The vulnerability specifically impacts devices utilizing Snapdragon processors in networking equipment, routers, switches, and wired infrastructure components that rely on Qualcomm's secure execution environment for network operations. The lack of proper input validation creates a pathway for malicious actors to manipulate memory structures through crafted network packets or buffer operations that traverse the TrustZone boundary. This issue stems from insufficient bounds checking mechanisms when handling memory buffers that are passed between the secure and non-secure execution environments within the Qualcomm chipset architecture. The vulnerability is particularly concerning as it operates at the intersection of hardware security and network infrastructure, where memory corruption can lead to complete system compromise and unauthorized access to sensitive network operations. According to CWE classification, this vulnerability maps to CWE-129: Improper Validation of Array Index, which encompasses issues where buffer boundaries are not properly validated before memory access operations. The flaw demonstrates characteristics consistent with CWE-787: Out-of-bounds Write, where insufficient validation allows for memory corruption through improper pointer handling.
The technical implementation of this vulnerability occurs when network data processing routines within the Snapdragon chipset's networking stack fail to validate the integrity of buffer pointers before passing them to TrustZone components. During normal operation, network packets are processed through various stages including parsing, validation, and secure execution handling where data may be copied or manipulated within memory buffers. When the system receives malformed or specially crafted network traffic, the absence of proper pointer validation allows an attacker to manipulate buffer boundaries or memory locations that should remain protected within the secure execution environment. The TrustZone security domain operates with elevated privileges and is designed to isolate sensitive operations from the main processing environment, but this vulnerability creates an entry point where unvalidated buffer pointers can cause memory corruption. The flaw specifically manifests when the system attempts to process network data through secure pathways where buffer sizes and pointer validity are not properly verified before memory operations occur. This creates opportunities for attackers to potentially execute arbitrary code within the secure environment or manipulate network processing functions that are meant to remain protected from external interference. The operational impact extends beyond simple memory corruption as it undermines the fundamental security guarantees provided by the TrustZone architecture, potentially allowing attackers to bypass security controls that are essential for maintaining network infrastructure integrity.
The exploitation of CVE-2020-11256 can result in severe operational consequences for organizations relying on Snapdragon-based networking equipment, particularly in enterprise and industrial environments where network infrastructure security is paramount. Attackers could leverage this vulnerability to gain unauthorized access to network management functions, manipulate routing tables, or compromise the integrity of secure network communications. The vulnerability's impact is amplified when considering that many networking devices operate continuously and may not receive regular security updates, particularly in industrial control systems or legacy infrastructure where patch management is challenging. Organizations using affected Snapdragon chipsets in network switches, routers, or wireless access points face potential exposure to man-in-the-middle attacks, network disruption, or complete system compromise. The vulnerability aligns with ATT&CK technique T1059.007: Command and Scripting Interpreter: Python, as attackers may utilize automated tools to probe for vulnerable systems and establish persistent access through compromised network infrastructure. Network administrators should consider this vulnerability as a potential vector for lateral movement within secured networks, as compromised networking equipment can serve as a foothold for broader attacks. The impact extends to supply chain security concerns, as manufacturers may unknowingly ship vulnerable networking equipment that could be exploited by adversaries targeting critical infrastructure. Organizations should also consider the potential for data exfiltration through manipulated network processing functions, where attackers could intercept or modify sensitive network communications that traverse the affected infrastructure.
Mitigation strategies for CVE-2020-11256 should focus on both immediate defensive measures and long-term architectural considerations for affected Snapdragon-based networking equipment. Immediate actions include implementing network segmentation to isolate vulnerable networking equipment from critical systems, deploying intrusion detection systems to monitor for anomalous network traffic patterns that may indicate exploitation attempts, and ensuring that network equipment firmware is updated with patches provided by Qualcomm or device manufacturers. Organizations should also consider disabling unnecessary network services and protocols on affected devices to reduce the attack surface. The vulnerability highlights the importance of implementing proper input validation mechanisms at multiple layers of network processing, including both software and hardware security boundaries. Device manufacturers should enhance their secure boot processes and implement additional runtime checks for buffer integrity within TrustZone components. Regular security assessments of network infrastructure should include vulnerability scanning for similar issues in other Qualcomm chipsets and security subsystems. The mitigation approach should also consider the implementation of network traffic monitoring that can detect malformed packets or unusual processing patterns that may indicate exploitation attempts. Organizations should develop incident response procedures specifically addressing TrustZone-based vulnerabilities, as these require specialized knowledge for both detection and remediation. Additionally, maintaining awareness of Qualcomm security advisories and implementing automated patch management processes for networking equipment can significantly reduce exposure time to this vulnerability. The remediation process must account for the fact that many networking devices in production environments may not support immediate hardware replacement, requiring careful planning for phased updates and continued monitoring of vulnerable systems.