CVE-2023-35649 in Android
Summary
by MITRE • 10/25/2023
In several functions of Exynos modem files, there is a possible out of bounds write due to a missing bounds check. This could lead to remote code execution with System execution privileges needed. User interaction is not needed for exploitation.
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Analysis
by VulDB Data Team • 10/31/2023
The vulnerability identified as CVE-2023-35649 represents a critical out-of-bounds write flaw within the Exynos modem implementation that affects multiple functions across the modem firmware. This vulnerability stems from the absence of proper bounds checking mechanisms in the code execution flow, creating a scenario where malicious data can be written beyond the allocated memory boundaries. The affected functions within the Exynos modem files demonstrate a fundamental failure in input validation and memory management practices, where the system does not adequately verify the size or range of data being processed before writing to memory locations. The absence of such checks creates a predictable attack surface that adversaries can exploit to manipulate memory contents beyond their intended boundaries.
The technical exploitation of this vulnerability can result in remote code execution with system-level privileges, making it particularly dangerous for mobile device security. The flaw operates at the kernel level within the modem subsystem, where the missing bounds check allows attackers to overwrite critical memory regions that control execution flow and system operations. This type of vulnerability falls under the Common Weakness Enumeration category CWE-787, which specifically addresses out-of-bounds write conditions that can lead to arbitrary code execution. The attack vector requires no user interaction, meaning that exploitation can occur automatically when the vulnerable modem processes malicious data packets or firmware updates, making it especially concerning for mobile networks and connected devices.
The operational impact of CVE-2023-35649 extends beyond simple memory corruption, as successful exploitation can enable full system compromise and persistent access to affected devices. Attackers leveraging this vulnerability can potentially gain complete control over the modem functionality, allowing them to intercept communications, modify network traffic, or establish backdoor access to the device. The system execution privileges required for exploitation indicate that the vulnerability operates at a privileged level within the modem's execution environment, making it particularly dangerous for mobile devices that rely heavily on modem functionality for network connectivity. This vulnerability directly aligns with ATT&CK technique T1059.007 for command and scripting interpreter, as successful exploitation could enable adversaries to execute arbitrary code and establish persistent access through the compromised modem subsystem.
Mitigation strategies for this vulnerability must address both the immediate firmware-level fixes and broader security architecture considerations. Device manufacturers should implement comprehensive bounds checking mechanisms in all modem-related functions and establish robust input validation processes to prevent similar issues in future implementations. The security community should also consider implementing runtime protections such as memory protection boundaries, stack canaries, and address space layout randomization to make exploitation more difficult. Additionally, regular firmware updates and security audits of modem implementations are essential to identify and remediate similar vulnerabilities before they can be exploited in the wild. Network operators should monitor for signs of exploitation attempts and implement network-level detection mechanisms to identify anomalous modem behavior that could indicate successful exploitation of this vulnerability.