CVE-2025-68255 in Linux
Summary
by MITRE • 12/16/2025
In the Linux kernel, the following vulnerability has been resolved:
staging: rtl8723bs: fix stack buffer overflow in OnAssocReq IE parsing
The Supported Rates IE length from an incoming Association Request frame was used directly as the memcpy() length when copying into a fixed-size 16-byte stack buffer (supportRate). A malicious station can advertise an IE length larger than 16 bytes, causing a stack buffer overflow.
Clamp ie_len to the buffer size before copying the Supported Rates IE, and correct the bounds check when merging Extended Supported Rates to prevent a second potential overflow.
This prevents kernel stack corruption triggered by malformed association requests.
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Analysis
by VulDB Data Team • 02/22/2026
The vulnerability identified as CVE-2025-68255 resides within the Linux kernel's staging driver for rtl8723bs wireless network adapters, representing a critical stack buffer overflow condition that could lead to kernel compromise. This flaw specifically affects the parsing of Association Request frames received from wireless stations, where the driver processes Information Element (IE) data structures without proper bounds checking. The issue manifests when the driver encounters a malformed Supported Rates Information Element that declares a length exceeding the allocated 16-byte stack buffer designated for supportRate storage. This fundamental design flaw creates a direct pathway for attackers to manipulate kernel memory through carefully crafted wireless frames, potentially enabling arbitrary code execution within kernel space.
The technical implementation of this vulnerability stems from improper input validation during the parsing of IEEE 802.11 management frames, particularly Association Request frames that contain Information Elements. The driver's OnAssocReq function directly utilizes the length field from the Supported Rates IE without verifying whether it exceeds the fixed 16-byte buffer capacity. This violates fundamental security principles of input validation and buffer management, creating a classic stack overflow scenario where malicious data can overwrite adjacent memory locations. The vulnerability is classified under CWE-121 Stack-based Buffer Overflow, which occurs when data is written beyond the boundaries of a fixed-length stack buffer. Additionally, the flaw demonstrates characteristics of CWE-129 Improper Validation of Array Index, as the code fails to validate that the index-based length specification aligns with the actual buffer capacity. The issue also aligns with ATT&CK technique T1059.001 Command and Scripting Interpreter: PowerShell, though in this case the attack vector involves wireless frame manipulation rather than script execution.
The operational impact of this vulnerability extends beyond simple denial of service, as it provides a potential pathway for privilege escalation and system compromise. An attacker positioned within wireless range of an affected system could craft Association Request frames with maliciously inflated IE lengths, triggering the buffer overflow when the kernel attempts to process these frames. The stack corruption could result in kernel panic, system instability, or more critically, enable attackers to execute arbitrary code with kernel privileges. This represents a significant risk in environments where wireless access points or stations are exposed to untrusted networks or where wireless management frames are not properly filtered. The vulnerability affects systems using the rtl8723bs driver, which is commonly found in various wireless network adapters and embedded systems, making the potential attack surface quite broad across different hardware platforms.
Mitigation strategies for CVE-2025-68255 should prioritize immediate patch application from kernel vendors, as the fix involves a straightforward bounds checking modification that clamps the IE length parameter to the buffer size before memory copying operations. System administrators should ensure their kernel versions include the resolved patch, which typically involves modifying the driver code to validate that ie_len does not exceed the 16-byte buffer capacity before performing memcpy operations. Network administrators should implement wireless frame filtering policies that can drop malformed Association Request frames or restrict wireless access to authenticated stations only. Additional defensive measures include monitoring for unusual wireless traffic patterns and implementing network segmentation to limit the potential impact of successful exploitation attempts. Organizations should also consider disabling unused wireless interfaces and ensuring that wireless network infrastructure properly validates incoming frames through proper IEEE 802.11 compliance checking mechanisms. The fix demonstrates the importance of defensive programming practices and proper input validation in kernel space, where memory corruption vulnerabilities can have catastrophic system-wide consequences.