CVE-2017-12132 : Vulnerability Insights and Analysis

The GNU C Library (glibc) vulnerability before version 2.26 could lead to off-path DNS spoofing attacks due to IP fragmentation.

Understanding CVE-2017-12132

When using glibc before version 2.26, the DNS stub resolver could request substantial UDP responses from name servers when EDNS support is active, making DNS spoofing attacks easier.

What is CVE-2017-12132?

The vulnerability in the DNS stub resolver of glibc could result in requesting large UDP responses from name servers, potentially simplifying off-path DNS spoofing attacks.

The Impact of CVE-2017-12132

Allows for off-path DNS spoofing attacks by leveraging IP fragmentation

Technical Details of CVE-2017-12132

The following technical details outline the vulnerability and its implications.

Vulnerability Description

The DNS stub resolver in glibc before version 2.26, with enabled EDNS support, can solicit large UDP responses from name servers, facilitating off-path DNS spoofing attacks.

Affected Systems and Versions

Product: Not applicable
Vendor: Not applicable
Versions: All versions before glibc 2.26

Exploitation Mechanism

The vulnerability exploits the DNS stub resolver in glibc, which triggers the solicitation of extensive UDP responses from name servers, potentially aiding in off-path DNS spoofing attacks.

Mitigation and Prevention

Protecting systems from CVE-2017-12132 involves immediate steps and long-term security practices.

Immediate Steps to Take

Update glibc to version 2.26 or newer to mitigate the vulnerability
Monitor DNS traffic for any suspicious activities

Long-Term Security Practices

Implement network segmentation to isolate critical systems
Regularly update and patch software to address security flaws

Patching and Updates

Apply patches provided by glibc to fix the vulnerability