CVE-2023-53363 is a high-severity vulnerability identified in the Linux kernel, specifically concerning a use-after-free error in the PCI subsystem. This vulnerability allows attackers to exploit the improper handling of resources during bus removal cleanup, potentially leading to unauthorized access or system instability. The CVSS score for this vulnerability is 7.8, indicating a high level of risk.
The vulnerability was first published on September 17, 2025, and has been marked as modified. Organizations utilizing affected Linux kernel versions should take immediate action to apply available patches and mitigate the risks associated with this vulnerability.
Risk to organizations includes potential unauthorized access and system crashes, which can lead to significant operational disruptions. Given the nature of this vulnerability and its exploitation status, organizations should prioritize patching immediately.
Currently, there are no known exploits in the wild, however, the potential for exploitation remains a concern. Therefore, organizations are urged to stay vigilant and ensure that their systems are updated.
Vulnerability Details
The vulnerability described in CVE-2023-53363 is a use-after-free condition affecting the function pci_bus_release_domain_nr() within the Linux kernel's PCI subsystem. This issue was introduced by commit c14f7ccc9f5d, which inadvertently created a flaw during the process of removing PCI buses. The vulnerability has been classified under CWE-416, indicating a use-after-free error.
The CVSS v3.1 score of 7.8 indicates a high severity level, with the following attributes: attack vector is local (AV:L), attack complexity is low (AC:L), privileges required are low (PR:L), and no user interaction is required (UI:N). The impacts on confidentiality, integrity, and availability are all rated as high (C:H, I:H, A:H).
The affected product is identified as the Linux kernel, specifically versions 6.2 through 6.2.11, along with various release candidates of version 6.3. The vulnerability was disclosed on September 17, 2025.
Technical Analysis
The root cause of this vulnerability lies in the improper management of memory during PCI bus removal. Specifically, the function pci_remove_root_bus() calls pci_remove_bus(), which frees the struct pci_bus. Subsequently, pci_bus_release_domain_nr() attempts to access the now-freed struct, leading to potential exploitation.
The attack vector for this vulnerability is local, meaning an attacker must have access to the system to exploit it. The attack complexity is low, requiring minimal knowledge of the system's architecture. Additionally, the privileges required are low, allowing a non-administrative user to potentially execute an attack.
User interaction is not required for this attack to be successful, which increases the risk for organizations. The potential impacts on confidentiality, integrity, and availability are all rated as high, indicating that successful exploitation could lead to significant data loss or system outages.
Risk & Impact Analysis
Organizations that deploy vulnerable versions of the Linux kernel face considerable risks. The potential blast radius is extensive, as this vulnerability could allow attackers to gain unauthorized access to sensitive data or disrupt critical system functions. Given the high severity and potential for exploitation, remediation should be prioritized.
The urgency for addressing this issue is elevated due to the critical nature of the vulnerability. Organizations should assess the risk based on their specific deployment and consider the implications of any potential exploitation. An effective approach to risk management will involve timely patching and ongoing monitoring for any signs of exploitation.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The following versions of the Linux kernel are affected by this vulnerability: versions 6.2 through 6.2.11, as well as release candidates 6.3:rc1, 6.3:rc2, 6.3:rc3, 6.3:rc4, 6.3:rc5, and 6.3:rc6. Organizations using these versions should take immediate action to patch their systems.
Mitigation & Remediation
Organizations should prioritize updating to the latest version of the Linux kernel to mitigate this vulnerability. The recommended action is to apply available patches from the Linux kernel maintainers. If patches are unavailable, organizations may consider implementing configuration hardening and network controls to reduce exposure to potential exploitation.
For further guidance and strategies on effective remediation, organizations can refer to our detailed penetration testing services and frameworks.
Detection Guidance
To effectively detect potential exploitation of this vulnerability, organizations should monitor for unusual log indicators, such as unexpected access attempts or irregular kernel behavior. Behavioral anomalies, network signatures, and system changes that deviate from normal operations should be closely scrutinized.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2023-53363 highlights the critical need for organizations to maintain up-to-date systems and rigorous security practices. As vulnerabilities in widely used components like the Linux kernel can have broad implications, security teams must prioritize proactive measures and continuously assess their threat landscape.
This vulnerability is indicative of the patterns in security flaws that arise from resource management errors. Organizations can learn from this incident by implementing robust review processes for code changes and ensuring that memory management is a priority during development.
For comprehensive insights into vulnerability management, organizations may refer to our guide on vulnerability management programs and our best practices for penetration testing to enhance security posture.
Finally, organizations should consider engaging in red teaming exercises to validate their defenses against real-world attack scenarios.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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