CVE-2014-9293 in NTP Daemon
Summary
by MITRE
The config_auth function in ntpd in NTP before 4.2.7p11, when an auth key is not configured, improperly generates a key, which makes it easier for remote attackers to defeat cryptographic protection mechanisms via a brute-force attack.
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Analysis
by VulDB Data Team • 03/01/2022
The vulnerability identified as CVE-2014-9293 resides within the Network Time Protocol daemon implementation in versions prior to 4.2.7p11. This issue specifically affects the config_auth function which handles authentication key configuration. When no authentication key is explicitly configured, the system generates a default key that lacks proper cryptographic strength. This flaw creates a significant security weakness that directly impacts the integrity and authenticity mechanisms of the NTP protocol.
The technical flaw manifests in the improper generation of cryptographic keys when authentication is enabled but no specific key is defined by the administrator. The generated key contains predictable elements or insufficient entropy, making it vulnerable to brute-force attacks. This vulnerability falls under the category of weak cryptographic key generation as classified by CWE-327, specifically addressing the improper implementation of cryptographic key generation mechanisms. The flaw represents a direct violation of the principle of least privilege and cryptographic best practices, as the system fails to generate cryptographically secure keys when required.
The operational impact of this vulnerability is substantial for network infrastructure security. Remote attackers can exploit this weakness to perform brute-force attacks against the generated authentication keys, potentially gaining unauthorized access to NTP services. This compromise can lead to various downstream security issues including time manipulation attacks, denial of service conditions, and potential network-wide disruption. The vulnerability directly maps to ATT&CK technique T1071.004 for Application Layer Protocol: DNS and T1566.002 for Phishing: Spearphishing Attachment, as attackers can leverage compromised NTP services to further their objectives. Organizations relying on NTP for time synchronization across critical infrastructure become particularly vulnerable to this attack vector.
Mitigation strategies for CVE-2014-9293 require immediate implementation of proper authentication key configuration. System administrators must ensure that explicit, strong authentication keys are configured for all NTP services rather than relying on default or automatically generated keys. The recommended approach involves generating cryptographically secure keys using appropriate randomness sources and implementing key rotation policies. Upgrading to NTP version 4.2.7p11 or later resolves the vulnerability by implementing proper key generation mechanisms. Additionally, network segmentation and access control measures should be enforced to limit exposure of NTP services to untrusted networks, while monitoring systems should be configured to detect unusual authentication attempts or time synchronization anomalies that might indicate exploitation attempts.