CVE-2018-7183 in Fujitsu M10-1
Summary
by MITRE
Buffer overflow in the decodearr function in ntpq in ntp 4.2.8p6 through 4.2.8p10 allows remote attackers to execute arbitrary code by leveraging an ntpq query and sending a response with a crafted array.
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Analysis
by VulDB Data Team • 07/17/2024
The vulnerability identified as CVE-2018-7183 represents a critical buffer overflow flaw within the Network Time Protocol implementation, specifically affecting ntpq utility versions 4.2.8p6 through 4.2.8p10. This vulnerability resides in the decodearr function which processes array data structures during ntpq query operations, creating a pathway for remote code execution through crafted array responses. The flaw stems from inadequate input validation and bounds checking within the array decoding mechanism, allowing attackers to overflow memory buffers and potentially execute arbitrary code on affected systems.
The technical implementation of this vulnerability demonstrates a classic buffer overflow condition where the decodearr function fails to properly validate the size of incoming array data before copying it into fixed-size buffers. This allows an attacker to send maliciously crafted ntpq responses containing oversized arrays that exceed the allocated buffer space, causing memory corruption and potential execution flow redirection. The vulnerability operates at the application layer and requires no authentication for exploitation, making it particularly dangerous in networked environments where ntpq queries are commonly processed.
The operational impact of CVE-2018-7183 extends beyond simple remote code execution to encompass complete system compromise, as the vulnerability can be leveraged by attackers to gain unauthorized access to time synchronization services. Network time protocol servers and clients that process ntpq queries become vulnerable attack vectors, potentially allowing adversaries to establish persistent backdoors, escalate privileges, or deploy additional malicious payloads. The vulnerability affects systems where ntpq is used for monitoring or managing time synchronization, including enterprise networks, critical infrastructure, and distributed computing environments.
Mitigation strategies for CVE-2018-7183 should prioritize immediate patching of affected ntp versions to 4.2.8p11 or later, which includes proper bounds checking and input validation fixes. Network administrators should implement firewall rules to restrict ntpq query access to trusted sources only, and consider disabling unnecessary ntpq functionality where possible. The vulnerability aligns with CWE-121, which catalogs buffer overflow conditions in stack-based memory allocation, and maps to ATT&CK technique T1059 for remote code execution through network services. Additional defensive measures include implementing network segmentation, monitoring for unusual ntpq query patterns, and conducting regular vulnerability assessments to identify similar buffer overflow conditions in other network services and applications.