CVE-2017-11104 : Exploit Details and Defense Strategies
Learn about CVE-2017-11104, a vulnerability in Knot DNS versions prior to 2.4.5 and 2.5.x up to 2.5.2 that allows attackers to bypass TSIG authentication. Find mitigation steps and long-term security practices here.
Knot DNS versions prior to 2.4.5 and 2.5.x up to 2.5.2 are vulnerable to a flaw in the TSIG protocol implementation that could allow attackers to bypass TSIG authentication under specific conditions.
Understanding CVE-2017-11104
This CVE entry describes a vulnerability in Knot DNS versions that could be exploited to bypass TSIG authentication.
What is CVE-2017-11104?
The vulnerability in CVE-2017-11104 is related to an incorrect check of the TSIG validity period in the TSIG protocol implementation of Knot DNS. Attackers with a valid key name and algorithm could exploit this flaw to bypass TSIG authentication if certain conditions are met.
The Impact of CVE-2017-11104
The vulnerability could enable attackers to bypass TSIG authentication in Knot DNS versions prior to 2.4.5 and 2.5.x up to 2.5.2, potentially leading to unauthorized access and manipulation of DNS data.
Technical Details of CVE-2017-11104
This section provides more technical insights into the CVE-2017-11104 vulnerability.
Vulnerability Description
The flaw in the TSIG protocol implementation of Knot DNS versions before 2.4.5 and 2.5.x before 2.5.2 allows attackers with a valid key name and algorithm to bypass TSIG authentication due to an improper TSIG validity period check.
Affected Systems and Versions
- Knot DNS versions prior to 2.4.5
- Knot DNS 2.5.x up to version 2.5.2
Exploitation Mechanism
Attackers can exploit this vulnerability by possessing a valid key name and algorithm, and if no additional ACL restrictions are in place, allowing them to bypass TSIG authentication.
Mitigation and Prevention
Protecting systems from CVE-2017-11104 requires immediate actions and long-term security practices.
Immediate Steps to Take
- Update Knot DNS to version 2.4.5 or 2.5.2 to mitigate the vulnerability.
- Implement additional ACL restrictions to enhance TSIG authentication security.
Long-Term Security Practices
- Regularly monitor and audit DNS configurations for any unauthorized changes.
- Educate staff on best practices for securing DNS servers and protocols.
Patching and Updates
- Stay informed about security advisories and updates from Knot DNS to apply patches promptly.