CVE-2014-9750 in ntp
Summary
by MITRE
ntp_crypto.c in ntpd in NTP 4.x before 4.2.8p1, when Autokey Authentication is enabled, allows remote attackers to obtain sensitive information from process memory or cause a denial of service (daemon crash) via a packet containing an extension field with an invalid value for the length of its value field.
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Analysis
by VulDB Data Team • 06/20/2022
The vulnerability described in CVE-2014-9750 affects the Network Time Protocol daemon implementation in NTP versions prior to 4.2.8p1, specifically when Autokey Authentication is enabled. This issue represents a critical security flaw that impacts the integrity and availability of time synchronization services across networked systems. The vulnerability stems from improper validation of extension field lengths within NTP packets, creating potential attack vectors that could compromise system security and reliability.
The technical flaw resides in the ntp_crypto.c file within the ntpd daemon where extension fields in NTP packets are processed without adequate validation of their length parameters. When Autokey Authentication is active, the system processes extension fields containing cryptographic information that must be properly validated. Attackers can exploit this by crafting malicious NTP packets with extension fields that contain invalid length values for their value fields. This improper handling causes the daemon to either access invalid memory locations or attempt to process malformed data structures, leading to unpredictable behavior.
The operational impact of this vulnerability manifests in two primary ways: information disclosure and denial of service. In the information disclosure scenario, remote attackers can potentially extract sensitive data from process memory by sending specially crafted packets that cause the daemon to dereference invalid memory addresses. This could expose cryptographic keys, authentication tokens, or other confidential information stored in the daemon's memory space. The denial of service aspect occurs when malformed extension fields cause the ntpd daemon to crash or terminate unexpectedly, disrupting time synchronization services for all systems relying on that particular NTP server.
This vulnerability aligns with CWE-125, which describes out-of-bounds read conditions, and CWE-129, which covers insufficient validation of length fields. The attack pattern follows techniques described in the MITRE ATT&CK framework under T1499 for endpoint denial of service and T1566 for credential access through network protocols. The flaw demonstrates a classic buffer overread condition where the system attempts to process data beyond the bounds of allocated memory regions. The vulnerability affects systems where NTP Autokey Authentication is enabled, which is commonly implemented in enterprise environments and critical infrastructure where precise time synchronization is essential for security operations.
The recommended mitigations include immediate patching to NTP version 4.2.8p1 or later, which contains the necessary validation fixes for extension field processing. Organizations should also consider disabling Autokey Authentication if it is not essential for their security requirements, as this removes the attack surface entirely. Network segmentation and firewall rules can be implemented to restrict NTP traffic to trusted sources only, reducing the potential impact of exploitation. Additionally, monitoring systems should be configured to detect unusual NTP packet patterns that might indicate exploitation attempts, and regular security audits should verify that NTP implementations are properly configured without unnecessary authentication features that could expose systems to such vulnerabilities.