CVE-2018-5865 in Android
Summary
by MITRE
While processing a debug log event from firmware in all Android releases from CAF using the Linux kernel (Android for MSM, Firefox OS for MSM, QRD Android) before security patch level 2018-07-05, an integer underflow and/or buffer over-read can occur.
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Analysis
by VulDB Data Team • 04/05/2023
The vulnerability described in CVE-2018-5865 represents a critical security flaw in the Linux kernel implementation used across various Android platforms including Android for MSM, Firefox OS for MSM, and QRD Android. This issue specifically manifests during the processing of debug log events originating from firmware components, affecting all Android releases that utilize the Code Aurora Forum (CAF) kernel implementations. The vulnerability exists within the kernel's handling of firmware debug information, creating potential pathways for malicious exploitation that could compromise system integrity and security.
The technical root cause of this vulnerability lies in improper input validation and handling of debug log event data structures within the kernel's firmware interaction subsystem. When processing debug log events from firmware components, the kernel fails to properly validate integer values that control buffer boundaries and memory access operations. This oversight leads to integer underflow conditions where signed integer values become unexpectedly negative, followed by subsequent buffer over-read operations that attempt to access memory locations beyond allocated buffer boundaries. The combination of these two conditions creates a scenario where attackers can manipulate firmware debug log data to trigger undefined behavior in kernel memory management.
The operational impact of CVE-2018-5865 extends beyond simple memory corruption, potentially enabling attackers to execute arbitrary code within kernel space or cause system crashes and instability. This vulnerability affects devices running Android versions prior to the security patch level 2018-07-05, making a significant portion of deployed mobile devices susceptible to exploitation. The flaw's presence in firmware debug processing means that even legitimate debug information from hardware components could serve as a vector for malicious activity, as attackers can craft debug log events that trigger the integer underflow and buffer over-read conditions. The vulnerability's exploitation could result in privilege escalation, denial of service conditions, or potentially full system compromise depending on the specific implementation details and attack surface.
Mitigation strategies for CVE-2018-5865 primarily focus on applying the security patches released by device manufacturers and the Android security team, specifically targeting the security patch level 2018-07-05 or later. Organizations should prioritize updating all affected devices to ensure the kernel properly validates integer values during firmware debug log processing. Additionally, implementing runtime protections such as kernel address space layout randomization and stack canaries can help mitigate potential exploitation attempts, though these measures provide only partial defense against this specific vulnerability. The fix typically involves correcting the integer validation logic in the kernel's firmware debug event handling code to prevent underflow conditions and ensure proper buffer boundary checks. This vulnerability aligns with CWE-190, which addresses integer overflow and underflow conditions, and may map to ATT&CK techniques involving privilege escalation and kernel exploitation within the system and network compromise domains.