CVE-2023-53788

Vulnerability

Analysis

CVE-2023-53788 is a buffer overrun vulnerability in the Linux kernel's ALSA HDA driver for Creative Sound Core3D (ca0132) audio chipsets. The bug resides in the tuning_ctl_set() function within sound/pci/hda/patch_ca0132.c. The function iterates over a fixed-size array ca0132_tuning_ctls looking for a matching NID (Node ID). If no match is found, the loop exits with i equal to TUNING_CTLS_COUNT (12), but the code then unconditionally indexes the array at position i, resulting in an out-of-bounds read on ca0132_tuning_ctls[i].mid [1].

Exploitation

To trigger this bug, an attacker must be able to invoke tuning_ctl_set() with a NID that does not correspond to any entry in the tuning control table. This likely requires local access to the system and the ability to interact with the audio device via ALSA control interface, possibly through a malicious audio application or crafted user-space input. No authentication is needed beyond local user access, and the attack surface is the HDA subsystem which is typically accessible to unprivileged processes.

Impact

Successful exploitation can cause an out-of-bounds array access, leading to a kernel crash (denial of service) or potentially arbitrary code execution in kernel context, depending on how the out-of-bounds value is used as a parameter to dspio_set_param(). The CVE description and static analysis (cppcheck) confirm the index overflow, but the concrete impact is limited to memory corruption within the kernel heap.

Mitigation

Patches have been applied to the Linux kernel stable branches. The fix adds a check after the loop to bail out if no matching NID is found, preventing the out-of-bounds access [1][2][3]. Users should update their kernel to a version that includes the stable commit. No workaround is available other than applying the patch or avoiding use of the vulnerable ca0132 driver.