CVE-2019-18805 : What You Need to Know

A vulnerability was found in the Linux kernel up to version 5.0.11, specifically in the file net/ipv4/sysctl_net_ipv4.c. The issue revolves around a signed integer overflow in net/ipv4/tcp_input.c, which occurs in the function tcp_ack_update_rtt(). This vulnerability can be exploited if a very large integer is written by userspace to the file /proc/sys/net/ipv4/tcp_min_rtt_wlen. The consequence of this vulnerability could be a denial of service attack or potentially other undefined impacts. This vulnerability is also known as CID-19fad20d15a6.

Understanding CVE-2019-18805

This section provides insights into the nature and impact of the CVE-2019-18805 vulnerability.

What is CVE-2019-18805?

CVE-2019-18805 is a vulnerability in the Linux kernel up to version 5.0.11, affecting the file net/ipv4/sysctl_net_ipv4.c. It involves a signed integer overflow in net/ipv4/tcp_input.c, specifically in the function tcp_ack_update_rtt().

The Impact of CVE-2019-18805

The vulnerability poses a risk of denial of service attacks or other potential impacts when a large integer is written to /proc/sys/net/ipv4/tcp_min_rtt_wlen by userspace.

Technical Details of CVE-2019-18805

This section delves into the technical aspects of CVE-2019-18805.

Vulnerability Description

The vulnerability stems from a signed integer overflow in the Linux kernel's net/ipv4/tcp_input.c, specifically in the tcp_ack_update_rtt() function.

Affected Systems and Versions

Linux kernel versions up to 5.0.11

Exploitation Mechanism

The vulnerability can be exploited by writing a very large integer to /proc/sys/net/ipv4/tcp_min_rtt_wlen from userspace.

Mitigation and Prevention

Learn how to mitigate and prevent the CVE-2019-18805 vulnerability.

Immediate Steps to Take

Apply relevant patches provided by the Linux kernel maintainers
Monitor official sources for security advisories

Long-Term Security Practices

Regularly update the Linux kernel to the latest stable version
Implement proper access controls and permissions

Patching and Updates

Stay informed about security updates and apply them promptly to mitigate risks.