CVE-2026-45531 in Android
Summary
by MITRE • 09/08/2026
In read_boot_region of fsck.c, there is a possible out of bounds read due to a heap buffer overflow. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.
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Analysis
by VulDB Data Team • 09/08/2026
The vulnerability identified in the read_boot_region function within fsck.c represents a critical security flaw characterized by an out-of-bounds read resulting from a heap buffer overflow. This type of memory corruption issue arises when the application fails to properly validate input data or array indices before accessing memory locations, leading to reads beyond the allocated boundaries of a heap-allocated buffer. In the context of filesystem checking utilities like fsck, such functions are typically invoked during system boot sequences or manual maintenance operations to verify and repair disk structures. The presence of this flaw indicates that the code does not adequately check whether the requested read operation exceeds the size of the destination buffer, allowing an attacker who can influence the input parameters passed to this function to trigger a memory access violation outside the intended allocation space.
From a technical perspective, heap buffer overflows are particularly dangerous because they affect dynamically allocated memory regions which often contain critical data structures such as pointers, length fields, or object headers used by the allocator itself. An out-of-bounds read in this context may not immediately cause a crash but can lead to information disclosure if sensitive data stored adjacent to the target buffer is leaked into application variables. More critically, depending on how the corrupted memory content is subsequently processed, it could facilitate further exploitation chains that compromise system integrity. The vulnerability aligns with Common Weakness Enumeration (CWE) identifiers such as CWE-125 Out-of-bounds Read and potentially CWE-787 out-of-bounds write if the overflow leads to subsequent writes through pointer manipulation or indirect memory access patterns common in low-level C programming errors.
The operational impact of this vulnerability is severe due to its potential for local privilege escalation without requiring additional execution privileges from the attacker. This implies that any user account with sufficient permissions to trigger the filesystem check routine, either directly by invoking fsck or indirectly through automated system maintenance tasks scheduled at boot time, can exploit this flaw. Since no user interaction is needed beyond initiating the process, which may occur automatically during normal system operation, the attack surface is significantly broadened. An attacker could potentially read kernel memory contents if the heap overlaps with higher-privileged regions or use the leaked information to craft more precise exploits targeting specific control flow mechanisms within the operating system core components loaded into memory alongside user-space applications.
This vulnerability maps closely to MITRE ATT&CK techniques related to initial access and privilege escalation, specifically those involving exploitation of software vulnerabilities for local code execution. The lack of required user interaction means that automated tools or scripts could be deployed remotely if there is any network-exposed service capable of triggering the vulnerable function via IPC mechanisms or shared filesystem mounts. Furthermore, because fsck operates with high privileges to ensure file system consistency, successful exploitation grants the attacker elevated rights equivalent to those held by the process executing the check, often root level on Unix-like systems. This enables complete compromise of the host including modification of security policies, installation of persistent backdoors, and exfiltration of confidential data stored locally.
Mitigation strategies must focus primarily on code hardening and defensive programming practices within the source file fsck.c. Developers should implement rigorous bounds checking before any memory access operation involving heap buffers to ensure that indices remain within valid limits defined by allocated sizes. Utilizing static analysis tools capable of detecting buffer overflow conditions during development phases is essential for identifying such logic errors early in the software lifecycle. Additionally, enabling compiler-based protections such as stack canaries, Address Space Layout Randomization (ASLR), and Full RELRO helps mitigate exploitation success rates even if the underlying vulnerability remains present. For system administrators, limiting access to filesystem checking utilities to trusted users only reduces exposure while patches are being developed and deployed by vendors addressing this specific defect in future releases of the affected software package.