CVE-2019-11190 : What You Need to Know

In versions of the Linux kernel prior to 4.8, a vulnerability exists that allows local users to bypass ASLR on setuid programs like /bin/su. This loophole is due to a race condition in the load_elf_binary() function, where install_exec_creds() is called too late, leading to issues with the ptrace_may_access() check.

Understanding CVE-2019-11190

This CVE identifier pertains to a security flaw in the Linux kernel that impacts the Address Space Layout Randomization (ASLR) feature.

What is CVE-2019-11190?

The vulnerability in the Linux kernel before version 4.8 enables local users to bypass ASLR on setuid programs by exploiting a timing issue in the load_elf_binary() function.

The Impact of CVE-2019-11190

The security issue poses a risk to the integrity of ASLR protection on setuid programs, potentially allowing unauthorized access to sensitive information.

Technical Details of CVE-2019-11190

This section delves into the specifics of the vulnerability.

Vulnerability Description

The flaw arises from the delayed invocation of install_exec_creds() in the load_elf_binary() function, leading to a race condition during the ptrace_may_access() check.

Affected Systems and Versions

Linux kernel versions prior to 4.8

Exploitation Mechanism

Local users can exploit the timing issue to bypass ASLR on setuid programs like /bin/su.

Mitigation and Prevention

Protective measures and actions to address the CVE-2019-11190 vulnerability.

Immediate Steps to Take

Update the Linux kernel to version 4.8 or newer to mitigate the vulnerability.
Monitor system logs for any suspicious activities that could indicate exploitation.

Long-Term Security Practices

Implement the principle of least privilege to restrict user access rights.
Regularly review and update security configurations to enhance system resilience.

Patching and Updates

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