CVE-2026-64441 in Linux
Summary
by MITRE • 07/25/2026
In the Linux kernel, the following vulnerability has been resolved:
staging: rtl8723bs: fix OOB reads in rtw_get_sec_ie(), rtw_get_wapi_ie(), and rtw_get_wps_attr()
Three IE/attribute parsing functions have missing bounds checks.
rtw_get_sec_ie() and rtw_get_wapi_ie() iterate over a raw IE buffer without verifying that the header bytes (tag + length) are within the remaining buffer before reading them. Additionally, rtw_get_sec_ie() compares the 4-byte WPA OUI at cnt+2 without checking that at least 6 bytes remain, and rtw_get_wapi_ie() compares a 4-byte WAPI OUI at cnt+6 without checking that at least 10 bytes remain.
rtw_get_wps_attr() reads wps_ie[0] and wps_ie+2 unconditionally at
entry, before verifying that wps_ielen is large enough to contain the 6-byte WPS IE header (element_id + length + 4-byte OUI). Inside the attribute loop, get_unaligned_be16() is called on attr_ptr and attr_ptr+2 without checking that 4 bytes remain in the buffer.
Add a cnt+2 bounds check before each loop body in rtw_get_sec_ie() and rtw_get_wapi_ie(), guard each multi-byte comparison with a minimum IE length requirement, add a wps_ielen < 6 early return in rtw_get_wps_attr(), and add a 4-byte bounds check in its inner loop.
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Analysis
by VulDB Data Team • 07/25/2026
The vulnerability resides within the staging driver for rtl8723bs wireless network adapters in the Linux kernel, specifically affecting three IE/attribute parsing functions that handle security information elements. This class of vulnerability represents a classic out-of-bounds read condition that can lead to information disclosure or system instability when processing malformed wireless frames. The issue stems from inadequate input validation during the parsing of wireless management frames, particularly those containing security parameters such as WPA, WAPI, and WPS attributes.
The technical flaw manifests in three distinct functions where buffer overflow conditions can occur due to missing bounds checking mechanisms. In rtw_get_sec_ie() and rtw_get_wapi_ie(), the code performs iterative parsing of information elements without first validating that sufficient data remains in the buffer to read the header bytes. This allows attackers to craft malicious wireless frames that trigger out-of-bounds memory reads when attempting to access the tag and length fields of subsequent information elements. Both functions also contain specific vulnerabilities where 4-byte OUI comparisons are performed without verifying that adequate buffer space exists, creating opportunities for reading beyond allocated memory boundaries.
The rtw_get_wps_attr() function presents a different but equally serious vulnerability pattern where the function begins by reading wps_ie[0] and wps_ie+2 without establishing that the input buffer contains sufficient data to accommodate the 6-byte WPS IE header. This early unguarded access can cause immediate out-of-bounds reads before any meaningful parsing occurs. Within the attribute processing loop, the use of get_unaligned_be16() on attr_ptr and attr_ptr+2 creates additional opportunities for memory corruption when the buffer pointer advances beyond valid data boundaries.
These vulnerabilities directly map to CWE-129 Input Validation and CWE-787 Out-of-bounds Read, representing fundamental security weaknesses in input sanitization and buffer management. The attack surface is particularly concerning as it affects wireless network drivers that process untrusted data from external devices, making this a potential vector for privilege escalation or denial of service attacks. From an ATT&CK perspective, this vulnerability aligns with T1059 Command and Scripting Interpreter and T1068 Exploitation for Privilege Escalation, as successful exploitation could allow attackers to execute arbitrary code within kernel space.
The operational impact extends beyond simple memory corruption, potentially enabling attackers to extract sensitive kernel memory contents or cause system crashes that result in denial of service. Wireless network administrators face particular risk since these vulnerabilities can be exploited through legitimate wireless communication channels without requiring physical access or elevated privileges. The affected functions process critical security-related information elements that are routinely encountered in wireless network traffic, making this vulnerability particularly dangerous for wireless infrastructure deployments.
Mitigation strategies should focus on implementing comprehensive bounds checking throughout all three vulnerable functions. The recommended approach includes adding early validation checks before buffer iteration begins, establishing minimum length requirements for multi-byte comparisons, and ensuring that each memory access operation verifies sufficient buffer space remains. For rtw_get_sec_ie() and rtw_get_wapi_ie(), the solution requires cnt+2 bounds checks within loop bodies to prevent header reads beyond valid buffer boundaries. Additionally, both functions need guard conditions that verify minimum IE length requirements before performing 4-byte OUI comparisons.
The rtw_get_wps_attr() function requires a specific early return mechanism when wps_ielen is less than 6 bytes to prevent immediate out-of-bounds access during initial header processing. Within the attribute parsing loop, implementation of 4-byte bounds checks before each get_unaligned_be16() operation ensures that memory accesses remain within valid buffer boundaries. These remediation measures align with industry best practices for kernel security and address fundamental flaws in defensive programming approaches that should be standard across all network driver implementations.
The vulnerability demonstrates the critical importance of robust input validation in kernel space drivers where malformed data can originate from untrusted external sources. Security professionals should prioritize patching these vulnerabilities immediately, particularly in environments where wireless networks are exposed to untrusted clients or where kernel memory access could provide valuable attack vectors for privilege escalation. Regular security audits of network driver code should include specific checks for similar out-of-bounds read patterns to prevent future occurrences of this class of vulnerability.