CVE-2022-21758 in MT6833
Summary
by MITRE • 06/06/2022
In ccu, there is a possible memory corruption due to a double free. This could lead to local escalation of privilege with System execution privileges needed. User interaction is not needed for exploitation. Patch ID: ALPS06439600; Issue ID: ALPS06439600.
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Analysis
by VulDB Data Team • 06/10/2022
The vulnerability identified as CVE-2022-21758 resides within the ccu component, representing a critical memory corruption issue stemming from an improper double free operation. This flaw manifests in the form of a memory management error that occurs when the same memory block is freed twice, creating a dangerous state where subsequent memory operations may corrupt adjacent data structures or execute arbitrary code. The vulnerability specifically affects systems where ccu operates as a privileged component, making it particularly concerning for escalation of privileges. The double free condition creates a scenario where attackers can manipulate heap memory layout to achieve unauthorized access to system resources, potentially enabling local privilege escalation to system execution privileges without requiring any user interaction.
The technical implementation of this vulnerability follows a classic heap corruption pattern where the ccu component fails to properly track memory allocation states, leading to a situation where a memory block can be freed more than once. When the second free operation occurs, the heap management structures become corrupted, potentially allowing an attacker to manipulate the freed memory to redirect execution flow or overwrite critical system data. This memory corruption can result in a range of outcomes from denial of service to full system compromise, depending on the specific memory layout and the attacker's ability to control the heap state. The vulnerability's classification under CWE-415 indicates it involves improper handling of memory allocation and deallocation, specifically the double free condition that violates fundamental memory safety principles.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it can potentially allow attackers to execute arbitrary code with elevated privileges, effectively compromising the entire system. Since no user interaction is required for exploitation, the vulnerability presents a significant risk to systems where ccu runs with elevated permissions, making it particularly dangerous in environments where such components operate with system-level privileges. The local nature of the attack means that an attacker must already have access to the system, but the privilege escalation aspect transforms a low-privilege position into one with complete system control. This vulnerability directly impacts system integrity and can lead to complete compromise of the affected device or system.
Mitigation strategies for CVE-2022-21758 should prioritize applying the vendor-provided patch identified by patch ID ALPS06439600 and issue ID ALPS06439600, which addresses the underlying double free condition in the ccu component. Organizations should also implement comprehensive memory safety monitoring and heap integrity checks to detect similar patterns in other components. The remediation process should include thorough testing of the patched component to ensure no regressions occur while maintaining system functionality. Additionally, implementing runtime protections such as heap canaries and address space layout randomization can provide additional defense in depth against similar memory corruption vulnerabilities. Security teams should monitor for related vulnerabilities in similar components and consider implementing automated vulnerability scanning to identify potential instances of the same memory management flaw across their infrastructure. The ATT&CK framework categorizes this vulnerability under privilege escalation techniques, specifically focusing on local privilege escalation methods that exploit memory corruption flaws.