CVE-2021-27364 is a high-severity vulnerability discovered in the Linux kernel, affecting versions up to 5.11.3. The flaw resides in the file drivers/scsi/scsi_transport_iscsi.c, where an unprivileged user can craft malicious Netlink messages. With a CVSS score of 7.1, the exploitability of this vulnerability is categorized as high.
Risk to organizations includes unauthorized access and potential system disruption. Attackers may leverage this vulnerability to execute local attacks, compromising system integrity and availability.
Given the severity of this vulnerability, organizations should prioritize patching immediately. The Linux community has released updates, and affected systems must be remediated promptly to mitigate risks.
This vulnerability has not been confirmed to have any public exploits available, but organizations should remain vigilant until a permanent solution is implemented.
For more detailed guidance on Linux kernel vulnerabilities, refer to our comprehensive resources on Linux security best practices.
Vulnerability Details
The Linux kernel through version 5.11.3 is affected by this vulnerability, which allows an unprivileged user to manipulate Netlink messages. This can lead to unauthorized access and potentially allow attackers to disrupt system services.
The CVSS score of 7.1 indicates a high severity level, which necessitates immediate action from security teams. Organizations leveraging affected Linux distributions such as Debian, Ubuntu, and others must ensure they deploy the patches provided by their respective vendors.
Technical Analysis
The root cause of CVE-2021-27364 stems from inadequate validation within the Linux kernel’s handling of Netlink messages. The attack vector is local, meaning an attacker must have access to the system. The attack complexity is rated as low, requiring minimal effort to exploit the vulnerability.
Privileges required are low, as the vulnerability can be exploited by users without administrative rights. User interaction is not required, making it easier for attackers to leverage this vulnerability.
The impact on confidentiality is high, allowing unauthorized access to sensitive information, while the integrity impact is none, as it does not alter data. Availability impact is high, potentially leading to service disruptions.
Risk & Impact Analysis
Organizations that deploy vulnerable versions of the Linux kernel face significant risks, including unauthorized access and system outages. The potential blast radius extends to any system utilizing the affected kernel versions.
Given the CVSS score of 7.1 and the absence of known exploits, the urgency is classified as high. Organizations should address this vulnerability in their priority patch cycle, prioritizing the remediation of systems exposed to this risk.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The vulnerability affects multiple versions of the Linux kernel, Debian Linux, and Ubuntu Linux, specifically:
• Linux Kernel versions up to 5.11.3 • Debian Linux version 9.0 • Ubuntu Linux versions 14.04, 16.04, 18.04, and 20.04
Mitigation & Remediation
Organizations should address this vulnerability by applying the necessary security patches provided by their respective Linux distributions. The patches are available through the official channels for Debian and Ubuntu.
If immediate patching is not feasible, consider implementing network controls to limit access to vulnerable systems and monitor for abnormal behavior that could indicate an exploit attempt.
For further guidance on securing Linux systems, organizations can refer to our article on Linux security best practices.
Detection Guidance
To detect potential exploitation attempts, organizations should monitor logs for unusual Netlink message patterns or suspicious user actions. Behavioral anomalies suggesting privilege escalation attempts should also be closely tracked.
Network signatures can be developed to identify malicious traffic associated with this vulnerability, enabling proactive defensive measures.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2021-27364 lies in its reflection of the ongoing security challenges within kernel development. As systems become increasingly complex, vulnerabilities like this highlight the need for rigorous security assessments throughout the development lifecycle.
Security teams should adopt a proactive approach, integrating regular security testing, including penetration testing, into their development processes to identify and mitigate similar vulnerabilities before they can be exploited.
For further insights on vulnerability management, organizations are encouraged to explore our resources on vulnerability management programs.
In summary, CVE-2021-27364 underscores the need for ongoing vigilance and comprehensive security practices to protect critical infrastructure.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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