CVE-2021-43395 : What You Need to Know
Discover the impact of CVE-2021-43395, a vulnerability in illumos, OmniOS, OpenIndiana, SmartOS, and Oracle Solaris systems, allowing local users to cause a deadlock and kernel panic.
An issue was discovered in illumos before f859e7171bb5db34321e45585839c6c3200ebb90, OmniOS Community Edition r151038, OpenIndiana Hipster 2021.04, and SmartOS 20210923. A local unprivileged user can cause a deadlock and kernel panic via crafted rename and rmdir calls on tmpfs filesystems. Oracle Solaris 10 and 11 are also affected.
Understanding CVE-2021-43395
What is CVE-2021-43395?
CVE-2021-43395 is a vulnerability found in illumos, OmniOS, OpenIndiana, SmartOS, and Oracle Solaris systems that allows a local unprivileged user to trigger a deadlock and kernel panic by exploiting specific file system operations.
The Impact of CVE-2021-43395
This vulnerability can lead to a denial of service (DoS) condition on the affected systems and potentially allow an attacker to disrupt system stability significantly.
Technical Details of CVE-2021-43395
Vulnerability Description
The vulnerability arises from improper handling of certain file system operations, specifically rename and rmdir calls on tmpfs filesystems, which can be exploited by a local unprivileged user.
Affected Systems and Versions
- illumos before f859e7171bb5db34321e45585839c6c3200ebb90
- OmniOS Community Edition r151038
- OpenIndiana Hipster 2021.04
- SmartOS 20210923
- Oracle Solaris 10 and 11
Exploitation Mechanism
The vulnerability can be exploited by a local unprivileged user through carefully crafted file operations like rename and rmdir on tmpfs filesystems, leading to a deadlock and eventual kernel panic.
Mitigation and Prevention
Immediate Steps to Take
- Apply patches provided by the respective vendors promptly.
- Monitor system logs for any unusual activities that might indicate exploitation attempts.
Long-Term Security Practices
- Regularly update and patch all software and systems to mitigate known vulnerabilities.
- Implement the principle of least privilege to restrict user capabilities and minimize the impact of potential attacks.
Patching and Updates
It is crucial to ensure that all affected systems are updated with the latest patches released by the vendors to address the vulnerability and enhance system security.