CVE-2023-40547 is a high-severity remote code execution vulnerability found in Red Hat's Shim. This vulnerability allows an attacker to exploit the Shim boot support by trusting attacker-controlled values when parsing an HTTP response. By crafting a specific malicious HTTP request, the attacker can achieve a completely controlled out-of-bounds write primitive, leading to a complete system compromise. This flaw is particularly concerning as it is only exploitable during the early boot phase. An attacker would need to perform a Man-in-the-Middle (MitM) attack or compromise the boot server to successfully exploit this vulnerability.
The CVSS score for this vulnerability is 8.3, indicating a high severity level. The attack vector is classified as adjacent network, and the attack complexity is high. Importantly, this vulnerability does not require any privileges or user interaction, which further heightens its risk potential. Organizations using affected systems must prioritize remediation to mitigate any potential exploitation risks.
Given the nature of this vulnerability and its potential for exploitation, organizations should address this issue in their priority patch cycle. Urgent action is required to protect systems from possible attackers seeking to leverage this vulnerability.
Risk to organizations includes the potential for complete system compromise if this vulnerability is exploited. The implications of such an event could be severe, resulting in data breaches, system downtimes, and substantial financial losses.
Vulnerability Details
The vulnerability identified in CVE-2023-40547 is classified as a remote code execution vulnerability affecting Red Hat's Shim. The flaw is due to the Shim boot support trusting attacker-controlled values when parsing an HTTP response. This vulnerability is classified under CWE-787 (Out-of-bounds Write) and CWE-346 (Origin Validation Error).
The CVSS score is 8.3, indicating a high severity. The attack vector is adjacent network, with a high attack complexity. No privileges are required, and user interaction is not needed, making this vulnerability particularly dangerous. Organizations utilizing Red Hat's Shim or Enterprise Linux versions prior to 15.8 need to be aware of this risk.
Technical Analysis
The root cause of CVE-2023-40547 is the failure of Shim to properly validate HTTP response content, leading to an out-of-bounds write condition. Attackers can exploit this vulnerability by sending specially crafted HTTP requests, which may allow them to manipulate the memory of the affected system.
The attack vector for this vulnerability is adjacent network, meaning that an attacker must be on the same network segment to exploit it. The complexity of the attack is high, requiring advanced skills to execute successfully. Importantly, no privileges are required for the attacker, and no user interaction is needed. The potential impacts of this vulnerability are severe, affecting confidentiality, integrity, and availability.
Risk & Impact Analysis
The real-world risk associated with CVE-2023-40547 is significant. Organizations that rely on Red Hat Shim or Enterprise Linux versions prior to 15.8 may face severe consequences if this vulnerability is exploited. The potential for complete system compromise means that sensitive data could be exposed or manipulated, leading to data breaches and loss of trust from clients and stakeholders.
The blast radius for this vulnerability could be extensive, particularly for organizations that operate critical infrastructure or handle sensitive information. Given the high CVSS score of 8.3 and the lack of a known exploit, organizations should still treat this vulnerability with a sense of urgency in their remediation efforts. Organizations should prioritize patching immediately.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
CVE-2023-40547 affects specific versions of Red Hat Shim and Enterprise Linux. The vulnerable versions include:
- Red Hat Shim versions prior to 15.8 - Red Hat Enterprise Linux versions 7.0, 8.0, and 9.0
Mitigation & Remediation
To mitigate this vulnerability, organizations should apply the relevant patches and updates provided by Red Hat. Ensure that systems are updated to at least Shim version 15.8 or the latest available version of Red Hat Enterprise Linux.
If immediate patching is not feasible, organizations may consider implementing additional network controls to help mitigate the risk. Monitoring network traffic for suspicious activity during the early boot phase can also be beneficial.
Continuous penetration testing can also help validate the effectiveness of the remediation efforts.
Detection Guidance
Organizations should monitor for log indicators that may suggest an attempt to exploit this vulnerability. Key indicators include abnormal HTTP requests and unexpected behavior during the early boot phase.
Behavioral anomalies in system startup or unusual network traffic patterns may also indicate a potential exploitation attempt. Implementing network signatures to detect such activities can further enhance security.
AppSecure Threat Intelligence Insight
CVE-2023-40547 highlights the ongoing challenges in maintaining secure boot processes and the risks associated with trusting external inputs during system initialization. Organizations must remain vigilant against such vulnerabilities, particularly in the context of increasingly sophisticated attack methodologies.
This vulnerability serves as a reminder for security teams to continuously improve their defenses against potential exploitation. Regular audits and assessments should be conducted to identify and remediate similar weaknesses in the boot process.
Penetration testing methodology should be integrated into the overall security strategy to ensure comprehensive coverage against emerging threats.
A vulnerability management program can aid in tracking and remediating vulnerabilities like CVE-2023-40547 effectively.
API penetration testing should also be considered as part of the security assessment strategy to protect against similar vulnerabilities.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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