CVE-2018-19591 Explained : Impact and Mitigation

Occurrences have been observed in the GNU C Library (also known as glibc or libc6) up to version 2.28, wherein an attempt to resolve a specifically constructed hostname using the getaddrinfo() function results in the creation of a socket descriptor that remains unclosed. This issue is connected to the if_nametoindex() function.

Understanding CVE-2018-19591

In the GNU C Library (aka glibc or libc6) through version 2.28, attempting to resolve a crafted hostname via getaddrinfo() leads to the allocation of a socket descriptor that is not closed. This is related to the if_nametoindex() function.

What is CVE-2018-19591?

The vulnerability in the GNU C Library allows for the creation of unclosed socket descriptors when resolving a specific hostname using the getaddrinfo() function, linked to the if_nametoindex() function.

The Impact of CVE-2018-19591

This vulnerability could be exploited by an attacker to exhaust resources on a targeted system, potentially leading to denial of service (DoS) conditions.

Technical Details of CVE-2018-19591

Vulnerability Description

The issue arises in the GNU C Library up to version 2.28, where resolving a crafted hostname with getaddrinfo() results in unclosed socket descriptors due to the if_nametoindex() function.

Affected Systems and Versions

Affected systems include those running GNU C Library versions up to 2.28.

Exploitation Mechanism

Crafting a specific hostname and attempting to resolve it using the getaddrinfo() function triggers the vulnerability, leading to the creation of unclosed socket descriptors.

Mitigation and Prevention

Immediate Steps to Take

Apply patches provided by the GNU C Library or system vendors promptly.
Monitor system resources for any unusual spikes in socket descriptor usage.

Long-Term Security Practices

Regularly update the GNU C Library and associated software to mitigate known vulnerabilities.
Implement network security measures to detect and prevent potential DoS attacks.

Patching and Updates

Stay informed about security advisories from the GNU C Library, vendors, and security organizations to apply relevant patches and updates in a timely manner.