CVE-2021-4150 is a medium-severity vulnerability affecting the Linux kernel. This vulnerability allows a local attacker with user privileges to cause a denial of service on the system. The root cause is a use-after-free flaw found in the add_partition function within block/partitions/core.c. When the device_add call fails while adding a partition to the disk, the lack of proper code cleanup can lead to system instability.
The vulnerability has a CVSS score of 5.5, which classifies it as medium severity. This score indicates that while the attack requires local access and low complexity, it can still significantly impact system availability. Therefore, organizations should prioritize patching to mitigate potential risks.
Risk to organizations includes possible service interruptions caused by local attackers exploiting this vulnerability. While there is no known public exploit, organizations should remain vigilant and apply any available patches as soon as possible.
Organizations should prioritize patching immediately to protect their systems from potential denial-of-service attacks stemming from this vulnerability.
Vulnerability Details
The vulnerability is categorized as a use-after-free flaw, specifically located in the add_partition function of the Linux kernel. The CVSS version 3.1 vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H, indicating a local attack vector, low attack complexity, and low privileges required.
The affected product is the Linux kernel, with all versions prior to 5.15 being vulnerable. The vulnerability was officially published on March 23, 2022.
The Common Weakness Enumeration (CWE) classification for this vulnerability is CWE-416, which signifies the use-after-free issue.
Technical Analysis
The root cause of CVE-2021-4150 is a failure to properly manage memory when the device_add function call fails. This oversight leads to a use-after-free condition. The attack vector is local, meaning that an attacker must have access to a user account on the system.
The attack complexity is low, as the vulnerability can be exploited without any special conditions. Only low privileges are required, and no user interaction is necessary for exploitation.
The impact on availability is high, as successful exploitation can lead to system crashes or service interruptions. However, confidentiality and integrity are not affected, as the vulnerability does not allow unauthorized data access or modification.
Risk & Impact Analysis
Real-world deployment risk for organizations includes potential denial of service caused by local attackers. The blast radius is limited to systems running vulnerable versions of the Linux kernel, thus affecting only those devices where the flaw can be exploited.
Given the nature of the vulnerability, organizations should assess the risk based on their environment and patch accordingly. The urgency is emphasized by the CVSS score of 5.5, indicating that while not critical, the risk of exploitation should not be overlooked.
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: all versions prior to 5.15, including release candidates (rc1 to rc6) of version 5.15.
Mitigation & Remediation
To mitigate this vulnerability, organizations should apply the latest patches available for the Linux kernel. The recommended version to upgrade to is 5.15 or newer, which includes fixes for this vulnerability. If immediate patching is not feasible, organizations should consider implementing additional network controls and monitoring solutions to detect any anomalous behavior.
For more effective security, organizations may also engage in penetration testing to identify similar vulnerabilities and ensure their systems are secure.
Detection Guidance
To detect potential exploitation of CVE-2021-4150, organizations should monitor logs for unusual activity related to the block subsystem. Behavioral anomalies such as system crashes or unexpected reboots can also be indicators of exploitation.
Additionally, network signatures that correlate with unusual patterns in partition management could help identify attempts to exploit this vulnerability.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2021-4150 lies in its representation of common coding pitfalls in kernel development, particularly the management of memory in critical functions. This vulnerability highlights the importance of proper memory management practices to prevent use-after-free errors.
Security teams should consider this incident as a learning opportunity to reinforce secure coding practices and enhance review processes for kernel code changes. To further strengthen security posture, investing in penetration testing methodologies can help proactively identify vulnerabilities similar to CVE-2021-4150.
Finally, organizations can benefit from implementing a robust vulnerability management program that includes regular assessments and updates to maintain security against emerging threats.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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