CVE-2017-11103 : Security Advisory and Response
Learn about CVE-2017-11103, a vulnerability in Heimdal before version 7.4 enabling remote attackers to impersonate services. Find out how to mitigate this security risk.
Heimdal before version 7.4 allows remote attackers to impersonate services through Orpheus' Lyre attacks due to a violation of the Kerberos 5 protocol specification. This CVE affects Heimdal and products embedding Heimdal code.
Understanding CVE-2017-11103
This CVE highlights a vulnerability in Heimdal that enables attackers to impersonate services, posing a significant security risk.
What is CVE-2017-11103?
The vulnerability in Heimdal before version 7.4 allows remote attackers to impersonate services through Orpheus' Lyre attacks. This is a result of a violation of the Kerberos 5 protocol specification.
The Impact of CVE-2017-11103
The vulnerability in Heimdal could lead to successful server impersonation and other malicious attacks, posing a severe threat to the security of affected systems.
Technical Details of CVE-2017-11103
Heimdal before version 7.4 is susceptible to Orpheus' Lyre attacks due to a flaw in the way it retrieves service-principal names.
Vulnerability Description
In the function _krb5_extract_ticket(), the KDC-REP service name should be obtained from the encrypted version stored in 'enc_part', rather than the unencrypted version stored in 'ticket'. This misuse of unencrypted data creates a potential for server impersonation and other attacks.
Affected Systems and Versions
- Product: Heimdal
- Vendor: N/A
- Versions affected: N/A
Exploitation Mechanism
The vulnerability allows remote attackers to impersonate services by exploiting the way Heimdal retrieves service-principal names, violating the Kerberos 5 protocol specification.
Mitigation and Prevention
It is crucial to take immediate steps to address and prevent the exploitation of CVE-2017-11103.
Immediate Steps to Take
- Update Heimdal to version 7.4 or newer to mitigate the vulnerability.
- Monitor for any suspicious activities on the network that could indicate exploitation of the vulnerability.
Long-Term Security Practices
- Regularly update and patch all software to prevent known vulnerabilities.
- Implement network segmentation and access controls to limit the impact of potential attacks.
Patching and Updates
- Ensure timely installation of security patches and updates provided by Heimdal to address CVE-2017-11103.