CVE-2019-19241 Explained : Impact and Mitigation

In the Linux kernel versions prior to 5.4.2, a vulnerability in the io_uring feature allows requests to have UID 0 and full capabilities unintentionally. This vulnerability, also known as CID-181e448d8709, affects various files such as fs/io-wq.c, fs/io_uring.c, and net/socket.c. Attackers can exploit this issue to bypass restrictions, like adding an IPv4 address to the loopback interface.

Understanding CVE-2019-19241

This CVE relates to a security flaw in the Linux kernel's io_uring feature that can lead to unintended privilege escalation.

What is CVE-2019-19241?

The vulnerability in the Linux kernel before version 5.4.2 allows certain operations to be executed with elevated privileges, even when requested by non-privileged users. This can be abused by attackers to perform unauthorized actions.

The Impact of CVE-2019-19241

The vulnerability enables attackers to bypass security restrictions and perform actions with elevated privileges, potentially leading to unauthorized access and manipulation of system resources.

Technical Details of CVE-2019-19241

This section provides detailed technical insights into the vulnerability.

Vulnerability Description

The issue in the io_uring feature of the Linux kernel allows requests to be processed with UID 0 and full capabilities, leading to unintended privilege escalation.

Affected Systems and Versions

Affected Systems: Linux kernel versions prior to 5.4.2
Affected Components: fs/io-wq.c, fs/io_uring.c, net/socket.c

Exploitation Mechanism

Attackers can exploit the vulnerability by leveraging certain IORING_OP_SENDMSG operations, which may be executed by kernel worker threads without considering the user's privilege context.

Mitigation and Prevention

Protecting systems from CVE-2019-19241 requires immediate actions and long-term security practices.

Immediate Steps to Take

Update to Linux kernel version 5.4.2 or later to mitigate the vulnerability.
Monitor system logs for any suspicious activities that could indicate exploitation attempts.

Long-Term Security Practices

Implement the principle of least privilege to restrict unnecessary access rights.
Regularly audit and review system configurations to identify and address security weaknesses.

Patching and Updates

Apply security patches provided by the Linux kernel maintainers to address the vulnerability and enhance system security.