CVE-2019-18806 Explained : Impact and Mitigation

The Linux kernel prior to version 5.3.5 has a memory leak vulnerability in the ql_alloc_large_buffers() function, allowing local users to launch denial of service attacks.

Understanding CVE-2019-18806

This CVE identifies a memory leak issue in the Linux kernel that can be exploited by local users.

What is CVE-2019-18806?

The vulnerability in the ql_alloc_large_buffers() function in the Linux kernel before version 5.3.5 enables local users to trigger denial of service attacks by causing pci_dma_mapping_error() failures.

The Impact of CVE-2019-18806

The vulnerability can lead to denial of service attacks, consuming significant amounts of memory and potentially disrupting system operations.

Technical Details of CVE-2019-18806

This section provides more technical insights into the vulnerability.

Vulnerability Description

The memory leak in the ql_alloc_large_buffers() function in drivers/net/ethernet/qlogic/qla3xxx.c allows local users to cause denial of service by triggering pci_dma_mapping_error() failures.

Affected Systems and Versions

Systems running Linux kernel versions prior to 5.3.5

Exploitation Mechanism

Local users can exploit the vulnerability to initiate denial of service attacks by triggering specific failures.

Mitigation and Prevention

Protecting systems from CVE-2019-18806 requires immediate actions and long-term security practices.

Immediate Steps to Take

Update the Linux kernel to version 5.3.5 or newer to mitigate the vulnerability.
Monitor system resources for any unusual memory consumption.

Long-Term Security Practices

Implement the principle of least privilege to restrict user access.
Regularly monitor and audit system logs for any suspicious activities.

Patching and Updates

Regularly apply security patches and updates to the Linux kernel to address known vulnerabilities.