CVE-2025-43539 in macOS
Summary
by MITRE • 12/12/2025
The issue was addressed with improved bounds checks. This issue is fixed in macOS Sonoma 14.8.3, macOS Sequoia 15.7.3. Processing a file may lead to memory corruption.
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Analysis
by VulDB Data Team • 12/17/2025
The vulnerability identified as CVE-2025-43539 represents a memory corruption issue that arises from insufficient bounds checking during file processing operations within Apple's operating systems. This weakness specifically affects macOS Sonoma versions prior to 14.8.3 and macOS Sequoia versions prior to 15.7.3, where improper validation of file boundaries can lead to unpredictable memory behavior. The flaw exists in the core file handling mechanisms that process external data inputs, creating potential attack vectors for malicious actors to exploit memory layout vulnerabilities.
The technical implementation of this vulnerability stems from inadequate input validation procedures that fail to properly verify file size limitations and boundary conditions during parsing operations. When a malformed or specially crafted file is processed, the system's memory management routines do not adequately restrict access to memory regions beyond the intended file boundaries. This condition creates opportunities for buffer overflows or memory corruption that can be leveraged to execute arbitrary code or cause system instability. The vulnerability aligns with CWE-129, which addresses insufficient bounds checking, and represents a classic example of how improper input validation can lead to memory safety issues. The flaw operates at the intersection of file parsing and memory management, where file data is read into memory buffers without proper size verification.
From an operational perspective, this vulnerability presents significant risks to system integrity and user security across affected macOS versions. Attackers could potentially craft malicious files designed to trigger the memory corruption during normal file processing activities such as opening documents, handling email attachments, or processing downloaded content. The impact extends beyond simple system crashes to potentially enable privilege escalation or remote code execution depending on the specific attack scenario. This vulnerability affects the fundamental security posture of macOS systems, particularly in environments where users frequently process external files or receive untrusted content through various channels. The issue demonstrates how seemingly benign file processing operations can become security threats when proper bounds checking mechanisms are absent.
The resolution for CVE-2025-43539 involves implementing enhanced bounds checking mechanisms that properly validate file size limitations and memory allocation boundaries before processing file content. Apple's patch addresses the root cause by strengthening input validation procedures and ensuring that all file processing operations include proper boundary verification before memory access occurs. Organizations should prioritize deployment of macOS Sonoma 14.8.3 and macOS Sequoia 15.7.3 updates to mitigate this vulnerability. Security teams should also implement monitoring for suspicious file processing activities and consider network-based detection measures that can identify potentially malicious file content before it reaches vulnerable systems. The mitigation strategy aligns with defensive programming principles and represents a fundamental security improvement that prevents the exploitation of memory corruption vulnerabilities through proper input validation and boundary enforcement.