CVE-2023-0386 is a high-severity vulnerability identified in the Linux kernel, specifically affecting the OverlayFS subsystem. This vulnerability allows unauthorized access to the execution of the setuid file with capabilities when a capable file is copied from a nosuid mount into another mount. The flaw enables local users to escalate their privileges on the system, posing a significant risk to the integrity and security of affected systems.
With a CVSS score of 7.8, this vulnerability is classified as high severity due to its potential impact on confidentiality, integrity, and availability. Attackers may leverage this vulnerability to gain unauthorized access, thereby compromising sensitive data and system functionality. Organizations should prioritize patching immediately to mitigate the risks associated with this vulnerability.
The vulnerability was published on March 22, 2023, and has been analyzed extensively. As of now, it is included in the Known Exploited Vulnerabilities (KEV) catalog, emphasizing its significance in the threat landscape. Security teams must be vigilant and ensure that any affected systems are remediated promptly.
Organizations are urged to assess their systems for this vulnerability and implement necessary patches or updates as soon as possible. Failure to address this issue could lead to significant security incidents and operational disruptions.
Vulnerability Details
A flaw was found in the Linux kernel, where unauthorized access to the execution of the setuid file with capabilities was found in the Linux kernel’s OverlayFS subsystem in how a user copies a capable file from a nosuid mount into another mount. This uid mapping bug allows a local user to escalate their privileges on the system.
This vulnerability is categorized under CWE-282, indicating improper ownership management, which can lead to privilege escalation.
Technical Analysis
The root cause of this vulnerability stems from a flaw in the uid mapping process within the OverlayFS subsystem of the Linux kernel. The attack vector is local, requiring low complexity and only low privileges to exploit. Notably, no user interaction is required, making it easier for an attacker to leverage this vulnerability.
The impacts of exploitation include high confidentiality, integrity, and availability risks, as attackers could gain unauthorized control over the system, potentially leading to data breaches and service disruptions.
Risk & Impact Analysis
Risk to organizations includes unauthorized privilege escalation, data compromise, and potential disruptions to services. The vulnerability affects a wide range of systems, including various distributions of Linux such as Debian and Ubuntu, as well as firmware for NetApp devices. The blast radius is significant, given the number of affected products and the critical nature of the Linux kernel in many infrastructures.
Organizations should assess their deployment of Linux systems to understand their exposure and prioritize remediation efforts based on the CVSS score and the known exploitation status. With the vulnerability marked as actively exploited, immediate action is required.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | Yes |
Public PoC | Yes |
Actively Exploited | Yes |
Ransomware Use | No |
Affected Versions
Affected systems include Debian Linux versions 10.0 and above, Ubuntu Linux versions 18.04, 20.04, and 22.04, as well as various firmware versions for NetApp devices. Specifically, versions of the Linux kernel from 5.11 to 6.1.9 are vulnerable, along with release candidates for version 6.2.
Mitigation & Remediation
Organizations should apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the affected products if mitigations are unavailable. To ensure security, regular updates and patches must be applied without delay.
For comprehensive security assessment, organizations can refer to our application security assessment services to identify vulnerabilities and improve security posture.
Detection Guidance
To detect potential exploitation of this vulnerability, organizations should monitor logs for unusual access patterns related to setuid files, validate user permissions, and track changes in system behavior that deviate from normal operation.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2023-0386 highlights the importance of robust ownership management in kernel subsystems. This vulnerability represents a pattern of privilege escalation risks that can arise from improper handling of file capabilities.
Security teams must stay vigilant against similar vulnerabilities and ensure that their patch management processes are effective. For further reading on best practices, refer to our blog on penetration testing methodology and the importance of timely vulnerability management.
Organizations can also benefit from insights on designing a vulnerability management program to proactively address risks before they can be exploited.
Finally, understanding the trends in ransomware attacks can help organizations to anticipate potential threats and enhance their defensive measures.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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