CVE-2022-49503 in Linux
Summary
by MITRE • 02/26/2025
In the Linux kernel, the following vulnerability has been resolved:
ath9k_htc: fix potential out of bounds access with invalid rxstatus->rs_keyix
The "rxstatus->rs_keyix" eventually gets passed to test_bit() so we need to ensure that it is within the bitmap.
drivers/net/wireless/ath/ath9k/common.c:46 ath9k_cmn_rx_accept() error: passing untrusted data 'rx_stats->rs_keyix' to 'test_bit()'
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Analysis
by VulDB Data Team • 10/21/2025
The vulnerability identified as CVE-2022-49503 resides within the Linux kernel's ath9k_htc wireless driver implementation, specifically affecting the ath9k_cmn_rx_accept function in the common.c source file. This issue represents a classic out-of-bounds memory access flaw that arises from insufficient input validation when processing received wireless frames. The vulnerability occurs during the processing of wireless reception status information where the driver receives an invalid key index value that subsequently gets passed to the test_bit() kernel function without proper bounds checking. The flaw demonstrates a clear failure in data validation practices, where untrusted input from wireless frame metadata is directly consumed without adequate sanitization or range verification.
The technical nature of this vulnerability stems from the driver's assumption that the rxstatus->rs_keyix field contains a valid index value within expected bounds. When this field contains an invalid value outside the acceptable range for the internal bitmap structure, the test_bit() function receives an argument that exceeds the maximum allowed bit position, potentially causing memory corruption or undefined behavior. This type of vulnerability falls under the CWE-129 weakness category, specifically addressing insufficient validation of the upper bounds of data items, and represents a direct violation of the principle of input validation that is fundamental to secure coding practices. The vulnerability is particularly concerning as it operates at the kernel level where such flaws can lead to privilege escalation or system instability.
The operational impact of CVE-2022-49503 extends beyond simple memory corruption, as it creates potential attack vectors for malicious wireless frames that could be crafted to exploit this out-of-bounds access. An attacker positioned within wireless network range could potentially craft specially formatted packets with invalid key index values to trigger the vulnerability, leading to system crashes, memory corruption, or in more severe cases, privilege escalation to kernel level execution. The vulnerability affects systems running Linux kernels with the ath9k_htc driver, which is commonly found in wireless network adapters from Atheros chipset manufacturers. This flaw aligns with ATT&CK technique T1068 by providing an avenue for local privilege escalation through kernel exploitation, and demonstrates how seemingly minor input validation gaps can create significant security risks in network device drivers.
Mitigation strategies for this vulnerability require immediate kernel updates from vendors that include the patched version of the ath9k_htc driver code. The fix implemented in the patch ensures that the rxstatus->rs_keyix value is properly validated against the maximum allowed bit position before being passed to test_bit(). Security administrators should prioritize applying kernel updates and monitoring for any exploitation attempts through network traffic analysis. Additional defensive measures include implementing network segmentation to limit wireless access points, deploying intrusion detection systems that monitor for suspicious wireless frame patterns, and conducting regular security audits of wireless infrastructure components. The vulnerability highlights the importance of robust input validation in kernel drivers and serves as a reminder that network device drivers represent critical attack surfaces requiring rigorous security testing and validation processes to prevent such out-of-bounds access scenarios.