CVE-2025-38599 in Linux
Summary
by MITRE • 08/19/2025
In the Linux kernel, the following vulnerability has been resolved:
wifi: mt76: mt7996: Fix possible OOB access in mt7996_tx()
Fis possible Out-Of-Boundary access in mt7996_tx routine if link_id is set to IEEE80211_LINK_UNSPECIFIED
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Analysis
by VulDB Data Team • 12/16/2025
The vulnerability CVE-2025-38599 represents a critical out-of-bounds memory access flaw within the Linux kernel's wireless subsystem, specifically affecting the mt7996 wireless driver implementation. This issue resides in the mt7996_tx() function which handles transmission operations for MediaTek mt7996 wireless network adapters. The flaw manifests when the link_id parameter is set to IEEE80211_LINK_UNSPECIFIED, a special value indicating an unspecified link identifier within the 802.11 wireless networking framework. This particular condition creates a scenario where the driver attempts to access memory locations beyond the allocated buffer boundaries, potentially leading to system instability or exploitation opportunities.
The technical root cause of this vulnerability stems from inadequate input validation within the wireless transmission routine. When link_id equals IEEE80211_LINK_UNSPECIFIED, the mt7996_tx() function fails to properly bounds-check array accesses or validate the link identifier against expected parameter ranges. This allows for arbitrary memory access patterns that can traverse beyond the intended data structures, potentially corrupting adjacent memory regions or accessing protected kernel memory. The vulnerability directly maps to CWE-129 Input Validation and Output Generation, specifically CWE-787 Out-of-bounds Write, as the function does not properly validate the link_id parameter before using it as an array index. The flaw represents a classic buffer overflow condition that can be triggered through malformed wireless transmission packets or improper driver state management.
The operational impact of this vulnerability extends beyond simple system crashes or hangs, as it presents potential attack vectors for privilege escalation and system compromise. An attacker capable of transmitting specially crafted wireless frames to a vulnerable system could exploit this condition to execute arbitrary code within kernel space, potentially leading to complete system takeover. The vulnerability affects systems running Linux kernels with MediaTek mt7996 wireless drivers, particularly those implementing 802.11 wireless networking functionality. The attack surface is significant as wireless network adapters are commonly found in laptops, desktops, servers, and embedded devices, making this a widespread concern for enterprise and consumer environments. This vulnerability aligns with ATT&CK technique T1068, which involves exploitation of local privileges, and can be leveraged for persistent access through kernel-level rootkit deployment.
Mitigation strategies for CVE-2025-38599 should prioritize immediate kernel updates from trusted sources, as the primary fix involves patching the mt7996_tx() function to include proper bounds checking for the link_id parameter. System administrators should implement network segmentation and wireless access controls to limit exposure, while monitoring for suspicious wireless traffic patterns that might indicate exploitation attempts. The fix requires validation of link_id values against expected ranges before using them as array indices, ensuring that IEEE80211_LINK_UNSPECIFIED is properly handled through conditional logic that prevents out-of-bounds memory access. Additionally, organizations should conduct vulnerability assessments to identify systems running affected kernel versions and implement automated patch management processes to maintain security posture. The mitigation approach should also include disabling unused wireless interfaces and implementing proper network access controls to reduce the attack surface for wireless-based exploitation attempts.