CVE-2022-49035 in Linux
Summary
by MITRE • 01/02/2025
In the Linux kernel, the following vulnerability has been resolved:
media: s5p_cec: limit msg.len to CEC_MAX_MSG_SIZE
I expect that the hardware will have limited this to 16, but just in case it hasn't, check for this corner case.
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Analysis
by VulDB Data Team • 01/22/2025
The vulnerability identified as CVE-2022-49035 resides within the Linux kernel's media subsystem, specifically affecting the s5p_cec driver component responsible for handling Consumer Electronics Control communications. This issue represents a classic buffer overflow condition that could potentially allow malicious actors to exploit memory boundaries through improper input validation. The s5p_cec driver manages CEC (Consumer Electronics Control) message transmission and reception for Samsung S5P platform devices, making it a critical component in television and multimedia device ecosystems where CEC protocols facilitate device communication and control.
The technical flaw manifests in the absence of proper bounds checking for message length parameters within the CEC message handling routine. While the hardware specification dictates that CEC message lengths should be limited to 16 bytes maximum, the kernel driver implementation failed to enforce this constraint through software validation. This oversight creates a potential buffer overflow scenario where a malformed CEC message could exceed the allocated buffer space, leading to memory corruption and potential privilege escalation. The vulnerability directly maps to CWE-129 Input Validation and CWE-787 Out-of-bounds Write, both of which are fundamental security weaknesses that have been consistently exploited in kernel space attacks.
The operational impact of this vulnerability extends beyond simple memory corruption, as it represents a potential pathway for privilege escalation within the Linux kernel environment. Attackers could craft malicious CEC messages with oversized payloads that bypass hardware limitations, potentially allowing them to overwrite adjacent memory regions and execute arbitrary code with kernel privileges. This risk is particularly concerning in embedded systems and consumer electronics devices where the kernel runs with elevated privileges and where physical access to CEC interfaces might be possible. The vulnerability could be exploited through various attack vectors including malicious CEC device emulation, network-based CEC message injection, or physical device manipulation that leverages the CEC bus for communication.
Mitigation strategies for CVE-2022-49035 should focus on implementing proper input validation and bounds checking within the kernel driver code. The fix requires enforcing the CEC_MAX_MSG_SIZE limit programmatically, ensuring that any message exceeding this threshold is either truncated or rejected before processing. Security teams should prioritize applying the kernel patch that implements this validation, as the vulnerability affects all systems running affected kernel versions with s5p_cec driver enabled. Additionally, system administrators should consider disabling CEC functionality when not required, particularly in environments where the risk of malicious CEC communication cannot be adequately controlled. The mitigation approach aligns with ATT&CK technique T1068, which involves exploiting vulnerabilities in legitimate system processes, and emphasizes the importance of kernel-level security hardening measures. Organizations should also implement monitoring for anomalous CEC traffic patterns and maintain updated kernel versions to protect against similar vulnerabilities in the broader Linux kernel ecosystem.