CVE-2024-49860 in Linux
Summary
by MITRE • 10/21/2024
In the Linux kernel, the following vulnerability has been resolved:
ACPI: sysfs: validate return type of _STR method
Only buffer objects are valid return values of _STR.
If something else is returned description_show() will access invalid memory.
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Analysis
by VulDB Data Team • 01/19/2026
The vulnerability identified as CVE-2024-49860 resides within the Linux kernel's ACPI subsystem, specifically addressing how the system handles the _STR method execution within the sysfs interface. This issue represents a critical validation flaw that could lead to arbitrary code execution or system instability. The problem manifests when the kernel processes ACPI _STR methods, which are designed to return string information about hardware components through the sysfs filesystem interface. The vulnerability stems from insufficient validation of return types from these ACPI methods, creating a potential attack vector where malicious firmware or hardware could manipulate the kernel's behavior through crafted return values.
The technical flaw occurs in the description_show() function which processes the output of _STR methods without proper validation of the return type. According to ACPI specification standards, the _STR method should exclusively return buffer objects containing string data. However, when other data types are returned, the kernel's processing logic fails to validate these inputs properly, leading to memory access violations. This validation failure creates a classic buffer overflow scenario where the kernel attempts to access memory locations that may not contain valid data or may be outside the allocated memory boundaries. The vulnerability directly maps to CWE-129, which addresses insufficient validation of the length of input data, and CWE-787, concerning out-of-bounds write operations.
The operational impact of this vulnerability extends beyond simple memory corruption, potentially enabling privilege escalation attacks or system crashes that could be exploited by malicious actors. An attacker with control over hardware or firmware components could craft malicious _STR method responses that would cause the kernel to access invalid memory locations during sysfs enumeration. This could result in denial of service conditions, data corruption, or in more sophisticated attack scenarios, arbitrary code execution within kernel space. The vulnerability affects systems running Linux kernels with ACPI support, particularly those that enumerate hardware components through sysfs interfaces, making it relevant to servers, desktops, and embedded systems that rely on ACPI for hardware management.
Mitigation strategies for CVE-2024-49860 primarily involve applying the official kernel patches that implement proper validation of _STR method return types before processing them in the description_show() function. System administrators should prioritize updating their kernel versions to include the fix, which typically involves adding explicit type checking to ensure that only buffer objects are processed from _STR methods. Additionally, organizations should implement monitoring for unusual sysfs activity or hardware enumeration patterns that might indicate exploitation attempts. The fix aligns with ATT&CK technique T1068, which covers privilege escalation through kernel vulnerabilities, and addresses the broader category of kernel exploitation techniques that target input validation flaws. Regular kernel updates and security audits should be maintained to prevent similar vulnerabilities from emerging in other ACPI methods or kernel subsystems.