CVE-2026-56967 in Android
Summary
by MITRE • 09/15/2026
In Cellular Modem, there is a possible out-of-bounds write due to a heap buffer overflow. This could lead to remote (proximal/adjacent) code execution with no additional execution privileges needed. User interaction is not needed for exploitation.
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Analysis
by VulDB Data Team • 09/15/2026
The identified vulnerability represents a critical security flaw within the cellular modem subsystem, specifically manifesting as an out-of-bounds write resulting from a heap buffer overflow. This type of memory corruption issue arises when software writes data beyond the allocated boundaries of a heap-allocated buffer, potentially overwriting adjacent metadata structures or other objects in memory. The presence of this vulnerability indicates a failure in input validation and bounds checking mechanisms within the modem firmware or its associated processing logic. Such flaws are particularly dangerous because they allow an attacker to manipulate the internal state of the system by corrupting critical data structures that govern memory management, such as heap metadata pointers like fd and bk fields used for managing free chunks.
The operational impact of this vulnerability is severe due to its potential for remote code execution with no additional privileges required. Since cellular modems often operate in a privileged context or have direct access to network interfaces, successfully exploiting this flaw could allow an adversary to execute arbitrary code on the device. The requirement for user interaction being absent makes this attack vector highly attractive for automated exploitation campaigns. An attacker positioned within proximal range of the target device can potentially trigger the overflow through specially crafted cellular signals or malformed data packets processed by the modem stack, leading to a complete compromise of the host system's integrity and confidentiality.
From a technical classification perspective, this vulnerability aligns with CWE-122, which denotes heap-based buffer overflows where memory is allocated on the heap rather than the stack. This distinction is significant because heap corruption often leads to more complex exploitation techniques involving control flow hijacking through pointer manipulation or arbitrary write primitives. Furthermore, in the context of adversary tactics and techniques, this vulnerability facilitates initial access and execution phases as defined by MITRE ATT&CK frameworks, specifically relating to remote code execution via network service vulnerabilities. The ability to achieve code execution without authentication underscores a critical gap in the security architecture of the cellular modem implementation.
Mitigation strategies must focus on both immediate remediation and long-term architectural improvements. Developers should implement rigorous input validation routines that strictly enforce buffer size limits before any write operations occur, ensuring that all data copied into heap-allocated buffers remains within their designated boundaries. Utilizing memory-safe programming languages or libraries for critical modem components can significantly reduce the risk of such low-level memory errors. Additionally, enabling compiler-based security features such as stack canaries, Address Space Layout Randomization (ASLR), and Data Execution Prevention (DEP) provides essential layers of defense that hinder exploitation even if a vulnerability is present. Regular static analysis scanning for buffer overflow patterns during the development lifecycle is also recommended to detect these issues early before deployment into production environments.