CVE-2023-53803 in Linux
Summary
by MITRE • 12/09/2025
In the Linux kernel, the following vulnerability has been resolved:
scsi: ses: Fix slab-out-of-bounds in ses_enclosure_data_process()
A fix for:
BUG: KASAN: slab-out-of-bounds in ses_enclosure_data_process+0x949/0xe30 [ses]
Read of size 1 at addr ffff88a1b043a451 by task systemd-udevd/3271
Checking after (and before in next loop) addl_desc_ptr[1] is sufficient, we
expect the size to be sanitized before first access to addl_desc_ptr[1].
Make sure we don't walk beyond end of page.
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Analysis
by VulDB Data Team • 03/29/2026
The vulnerability CVE-2023-53803 represents a critical slab-out-of-bounds memory access issue within the Linux kernel's SCSI subsystem, specifically affecting the ses_enclosure_data_process function in the ses enclosure driver. This flaw manifests as a kernel address sanitizer (KASAN) detection indicating a read operation of size 1 occurring at address ffff88a1b043a451, where the problematic access originates from the systemd-udevd process with task identifier 3271. The vulnerability stems from inadequate bounds checking in the processing of enclosure data structures, creating a potential pathway for memory corruption that could be exploited by malicious actors with kernel-level access or through specific attack vectors targeting the SCSI subsystem.
The technical root cause of this vulnerability lies in the insufficient validation of array bounds within the ses_enclosure_data_process function, which processes additional descriptor pointers without proper boundary verification. The kernel code fails to ensure that addl_desc_ptr[1] access remains within allocated memory boundaries, particularly when traversing page-sized data structures. This flaw represents a classic buffer overread condition where the code assumes safe access patterns without proper input sanitization or bounds checking before dereferencing array elements. The vulnerability specifically affects the SCSI Enclosure Services (SES) subsystem which handles enclosure management for storage devices, making it particularly concerning for enterprise storage environments where such subsystems are heavily utilized.
The operational impact of CVE-2023-53803 extends beyond simple memory corruption, potentially enabling privilege escalation attacks and system instability in environments utilizing SCSI storage infrastructure. When exploited, this vulnerability could lead to kernel memory corruption, system crashes, or more severe consequences including privilege escalation to kernel mode. The attack surface is primarily limited to systems with active SCSI enclosure management capabilities, but given the widespread use of SCSI storage in enterprise environments, the potential impact remains significant. The vulnerability affects systems running Linux kernels where the SES driver is enabled and actively processing enclosure data, particularly those with storage arrays or tape libraries that utilize SES protocols for management and monitoring.
Mitigation strategies for CVE-2023-53803 should focus on immediate kernel updates to versions containing the patched ses_enclosure_data_process function, which implements proper bounds checking before accessing addl_desc_ptr[1] elements. System administrators should prioritize patching affected systems, particularly those running enterprise storage solutions or systems with active SCSI enclosure management. Additional defensive measures include implementing kernel lockdown mechanisms, restricting access to SCSI subsystem interfaces, and monitoring for anomalous memory access patterns in kernel space. The fix addresses the underlying CWE-129 issue related to insufficient bounds checking in the code, aligning with ATT&CK technique T1068 which covers privilege escalation through kernel vulnerabilities. Organizations should also consider implementing runtime monitoring for KASAN detection and memory access violations to identify potential exploitation attempts. Given the nature of this vulnerability, regular security assessments of kernel components and proactive vulnerability management are essential for maintaining system integrity in environments where SCSI storage subsystems are actively utilized.