CVE-2023-40238 is a medium-severity vulnerability discovered in the BmpDecoderDxe component of Insyde InsydeH2O firmware. This vulnerability allows for crafted BMP logo files to be processed in a manner that can cause data to be copied to a specific memory address during the DXE phase of UEFI execution. The issue is attributed to an integer signedness error related to PixelHeight and PixelWidth during RLE4/RLE8 compression.
The CVSS score for this vulnerability is 5.5, classifying it as medium severity. It presents a local attack vector with low complexity, where the attacker requires low privileges and no user interaction is necessary. The primary impact of this vulnerability is on availability, as it can cause system disruptions in affected devices.
Organizations utilizing affected versions of Fujitsu hardware should be aware of the real-world risks posed by this vulnerability. Given the availability impact, potential disruptions in critical operations may arise if this issue is exploited.
The vulnerability was published on December 7, 2023, and affects various firmware versions of InsydeH2O, specifically for multiple models of Fujitsu devices.
Organizations should prioritize patching this vulnerability in their systems to mitigate the risks associated with its exploitation. Timely updates can prevent potential service interruptions and ensure system integrity.
Vulnerability Details
The vulnerability allows for the manipulation of BMP logo files, leading to unintended data copying during UEFI execution. This issue arises specifically in versions of InsydeH2O kernel 5.2 and later, up to specific patch versions, affecting devices from Lenovo and Fujitsu.
The official CVE description states: 'A LogoFAIL issue was discovered in BmpDecoderDxe in Insyde InsydeH2O with kernel versions 5.2 before 05.28.47, 5.3 before 05.37.47, 5.4 before 05.45.47, 5.5 before 05.53.47, and 5.6 before 05.60.47 for certain Lenovo devices.'
The vulnerability is classified under CWE-312, indicating a potential issue with improper handling of image data that can result in memory corruption.
Technical Analysis
The root cause of CVE-2023-40238 is an integer signedness error that occurs when processing BMP files. This error allows for data to be copied to a specific address, which can lead to system instability or crashes during the DXE phase of UEFI execution.
The attack vector is local, meaning an attacker must have physical access to the device or be able to execute code in the environment where the firmware operates. The attack complexity is low, allowing for exploitation with minimal effort. Furthermore, the attacker only requires low privileges, and no user interaction is needed for the attack to succeed.
In terms of impacts, the vulnerability primarily affects the availability of the system, potentially leading to crashes or service interruptions. The confidentiality and integrity impacts are rated as none, indicating that data exposure or corruption is not a direct consequence of this vulnerability.
Risk & Impact Analysis
Risk to organizations includes the potential disruption of services due to system crashes or instability triggered by exploitation of this vulnerability. Given that the attack complexity is low and the necessary privileges required are minimal, organizations should consider this a significant risk.
The blast radius of this vulnerability is limited to specific Fujitsu firmware versions and models. However, considering the critical nature of firmware in system operation, the impact may extend beyond individual devices, potentially affecting broader operational capabilities.
With a CVSS score of 5.5, organizations should address this vulnerability in their priority patch cycle. Immediate action can help mitigate potential risks associated with its exploitation.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
All versions of InsydeH2O firmware prior to the specified patch versions are affected by this vulnerability. Specifically, it impacts versions 5.2 before 05.28.47, 5.3 before 05.37.47, 5.4 before 05.45.47, 5.5 before 05.53.47, and 5.6 before 05.60.47.
Mitigation & Remediation
To mitigate this vulnerability, organizations should ensure that they upgrade to the latest firmware versions provided by Fujitsu and Insyde. Specific updates should be applied immediately to prevent potential exploitation.
If a patch is not immediately available, organizations should consider implementing additional security controls such as network segmentation and monitoring for unusual system behavior. Effective logging and alerting mechanisms should also be established to detect any potential exploit attempts.
For further information on security assessments and remediation strategies, organizations can refer to our application security assessment services.
Detection Guidance
To detect potential exploitation attempts of this vulnerability, organizations should monitor for specific log indicators related to firmware interactions and BMP file processing. Any anomalies in system behavior during the DXE phase should be logged and analyzed for further investigation.
Establishing behavioral baselines will help in identifying deviations that may indicate an attempted exploitation of this vulnerability.
AppSecure Threat Intelligence Insight
The discovery of CVE-2023-40238 highlights the importance of rigorous security practices in firmware development and maintenance. The issue represents a potential vector for local attacks, emphasizing the need for comprehensive security assessments on firmware and hardware.
Security teams should take this as an opportunity to review firmware security protocols and ensure that robust validation processes are in place to prevent similar vulnerabilities in the future. Engaging in regular penetration testing can help identify weaknesses in the firmware that may not be immediately apparent.
Additionally, understanding the patterns and trends surrounding firmware vulnerabilities can guide strategic defensive planning. For more insights on the latest security trends, consider reviewing our penetration testing methodology and vulnerability management program design guides.
Organizations should continuously assess their security posture and adapt to emerging threats to ensure the integrity and availability of their systems.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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