CVE-2009-1252 in ntp
Summary
by MITRE
Stack-based buffer overflow in the crypto_recv function in ntp_crypto.c in ntpd in NTP before 4.2.4p7 and 4.2.5 before 4.2.5p74, when OpenSSL and autokey are enabled, allows remote attackers to execute arbitrary code via a crafted packet containing an extension field.
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Analysis
by VulDB Data Team • 12/29/2024
The vulnerability identified as CVE-2009-1252 represents a critical stack-based buffer overflow in the Network Time Protocol daemon implementation. This flaw exists within the crypto_recv function located in ntp_crypto.c file of ntpd software. The vulnerability affects versions prior to 4.2.4p7 and 4.2.5p74, making it a significant concern for systems running these older versions. The flaw specifically manifests when both OpenSSL cryptographic libraries and autokey functionality are enabled simultaneously, creating a dangerous combination that exposes systems to remote code execution attacks.
The technical nature of this vulnerability stems from improper input validation within the extension field processing of NTP packets. When ntpd receives a crafted packet containing a maliciously constructed extension field, the crypto_recv function fails to properly bounds-check the incoming data before copying it into a fixed-size stack buffer. This classic buffer overflow condition allows an attacker to overwrite adjacent stack memory locations, potentially including return addresses and function pointers. The attack vector requires network access to send specially crafted NTP packets to the vulnerable system, making it a remote exploit that can be executed without authentication.
The operational impact of this vulnerability is severe and multifaceted. Remote attackers can leverage this buffer overflow to execute arbitrary code with the privileges of the ntpd process, typically running with elevated system permissions. This could lead to complete system compromise, allowing attackers to establish persistent backdoors, escalate privileges, or use the compromised system as a launching point for further attacks within the network infrastructure. Given that NTP is a critical service for time synchronization across networked systems, compromising an NTP server can have cascading effects on network operations and security monitoring systems. The vulnerability also aligns with CWE-121 Stack-based Buffer Overflow, which specifically addresses buffer overflows occurring in stack memory regions.
Mitigation strategies for CVE-2009-1252 primarily focus on immediate software updates to patched versions of NTP. Organizations should prioritize upgrading to NTP versions 4.2.4p7 or 4.2.5p74, which contain the necessary fixes for this vulnerability. Additionally, network administrators should consider implementing firewall rules to restrict NTP traffic to trusted sources only, reducing the attack surface. The ATT&CK framework categorizes this vulnerability under T1059 Command and Scripting Interpreter and T1203 Exploitation for Client Execution, highlighting the need for comprehensive network monitoring and intrusion detection system configurations. System hardening measures including disabling unnecessary NTP features, implementing proper access controls, and maintaining regular security updates form essential components of a layered defense strategy against such exploits.