CVE-2019-14821 Explained : Impact and Mitigation
Discover the impact of CVE-2019-14821, a high-severity vulnerability in the Linux kernel up to version 5.3. Learn about the exploitation risk and mitigation steps to secure your system.
A vulnerability was discovered in the Linux kernel, affecting versions up to 5.3. This flaw in the Coalesced MMIO write operation implementation within the KVM hypervisor can be exploited by an unprivileged user to crash the host kernel, potentially leading to a denial of service or elevated privileges.
Understanding CVE-2019-14821
This CVE involves a memory access vulnerability in the Linux kernel, impacting versions up to 5.3.
What is CVE-2019-14821?
The vulnerability allows an unprivileged user to crash the host kernel by exploiting the Coalesced MMIO write operation within the KVM hypervisor.
The Impact of CVE-2019-14821
- CVSS Base Score: 7.5 (High)
- Attack Vector: Local
- Attack Complexity: High
- Privileges Required: Low
- User Interaction: None
- Scope: Changed
- Confidentiality Impact: None
- Integrity Impact: High
- Availability Impact: High
- CWE ID: CWE-787
Technical Details of CVE-2019-14821
This section provides detailed technical information about the vulnerability.
Vulnerability Description
The vulnerability allows unauthorized access to memory beyond the allocated space in the Linux kernel, affecting versions up to 5.3.
Affected Systems and Versions
- Affected Product: Kernel
- Vendor: Linux
- Affected Versions: All through 5.3
Exploitation Mechanism
- The flaw resides in the Coalesced MMIO write operation within the Linux kernel's KVM hypervisor.
- By manipulating the designated MMIO ring buffer, an attacker can crash the host kernel.
Mitigation and Prevention
Protecting systems from CVE-2019-14821 requires immediate actions and long-term security practices.
Immediate Steps to Take
- Apply security patches provided by the vendor promptly.
- Monitor vendor advisories and security mailing lists for updates.
- Restrict access to '/dev/kvm' device to authorized users only.
Long-Term Security Practices
- Regularly update and patch the Linux kernel to mitigate known vulnerabilities.
- Implement least privilege access controls to limit the impact of potential exploits.
Patching and Updates
- Refer to vendor-specific security advisories for patch availability and installation instructions.