CVE-2024-52878 in InsydeH2O
Summary
by MITRE • 05/15/2025
An issue was discovered in Insyde InsydeH2O kernel 5.2 before version 05.29.50, kernel 5.3 before version 05.38.50, kernel 5.4 before version 05.46.50, kernel 5.5 before version 05.54.50, kernel 5.6 before version 05.61.50, and kernel 5.7 before version 05.70.50. In VariableRuntimeDxe driver, VariableServicesSetVariable () can be called by gRT_>SetVariable () or the SmmSetSensitiveVariable () or SmmInternalSetVariable () from SMM. In VariableServicesSetVariable (), it uses StrSize () to get variable name size, uses StrLen () to get variable name length and uses StrCmp () to compare strings. These actions may cause a buffer over-read.
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Analysis
by VulDB Data Team • 08/15/2025
The vulnerability identified as CVE-2024-52878 resides within the Insyde InsydeH2O kernel implementations across multiple versions, specifically affecting kernel versions 5.2 through 5.7 before their respective patched releases. This issue manifests in the VariableRuntimeDxe driver component which handles runtime variable management through the VariableServicesSetVariable() function. The flaw represents a classic buffer over-read condition that occurs when processing variable names through string manipulation functions without proper bounds checking. The vulnerability is particularly concerning as it operates at the kernel level within the UEFI environment, where it can potentially be exploited to gain elevated privileges or execute arbitrary code.
The technical implementation of this vulnerability stems from improper handling of string operations within the VariableServicesSetVariable() function. When the function processes variable names, it employs StrSize() to determine the variable name size, StrLen() to calculate the variable name length, and StrCmp() for string comparisons. These operations create a scenario where the buffer boundaries are not properly validated, allowing for potential over-read conditions. The flaw occurs because the function does not adequately verify that the string operations remain within allocated memory boundaries, particularly when dealing with variable-length names. This type of vulnerability falls under CWE-121, which describes stack-based buffer overflow conditions, though in this case it manifests as an over-read rather than a traditional overflow.
The operational impact of this vulnerability extends beyond typical software flaws due to its location within the UEFI kernel environment. Attackers who can trigger the vulnerable code path may exploit this over-read condition to access sensitive memory regions, potentially extracting confidential information or manipulating system state. The vulnerability can be triggered through legitimate calls to gRT->SetVariable() or through SMM (System Management Mode) functions SmmSetSensitiveVariable() and SmmInternalSetVariable(), making it accessible through multiple attack vectors. Since UEFI firmware operates at a privileged level and maintains system integrity, exploitation of this vulnerability could lead to complete system compromise, bypassing traditional operating system security controls and potentially enabling persistent backdoor access.
Mitigation strategies for CVE-2024-52878 should prioritize immediate firmware updates to the patched versions of InsydeH2O kernel as specified in the advisory. Organizations should implement comprehensive firmware inventory management to identify all affected systems and ensure timely patch deployment. The vulnerability's nature suggests that runtime monitoring and input validation should be enhanced at the firmware level, particularly for variable name handling operations. Security teams should also consider implementing firmware integrity monitoring solutions that can detect unauthorized modifications to UEFI components. Additionally, since this vulnerability operates within the SMM context, system administrators should review and harden SMM configurations to limit unnecessary access to sensitive firmware interfaces, following ATT&CK technique T1068 which addresses privilege escalation through system management mode. The fundamental fix requires proper bounds checking in all string operations within the VariableServicesSetVariable() function to prevent buffer over-read conditions.