CVE-2017-10982 in FreeRADIUS
Summary
by MITRE
An FR-GV-205 issue in FreeRADIUS 2.x before 2.2.10 allows "DHCP - Buffer over-read in fr_dhcp_decode_options()" and a denial of service.
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Analysis
by VulDB Data Team • 12/13/2022
The vulnerability identified as CVE-2017-10982 represents a critical buffer over-read condition within the FreeRADIUS authentication server software version 2.x prior to 2.2.10. This issue specifically affects the DHCP option decoding functionality, where the fr_dhcp_decode_options() function fails to properly validate input data lengths before processing DHCP options. The flaw arises from insufficient bounds checking in the DHCP protocol handling code, creating a scenario where maliciously crafted DHCP packets can trigger memory access violations. This vulnerability falls under the CWE-129 category of Improper Validation of Array Index, which directly relates to the buffer over-read condition that occurs when the software attempts to read memory beyond the allocated buffer boundaries.
The operational impact of this vulnerability extends beyond simple denial of service, as it represents a potential pathway for attackers to disrupt network authentication services that rely on FreeRADIUS for DHCP option processing. When a malicious DHCP packet is processed by the vulnerable FreeRADIUS server, the over-read condition can cause the service to crash or become unresponsive, effectively terminating legitimate authentication requests and creating a denial of service scenario for network users. The attack vector requires an attacker to send specially crafted DHCP packets to a FreeRADIUS server that is configured to process DHCP options, which is common in enterprise environments where RADIUS servers handle both authentication and DHCP services. This vulnerability maps to ATT&CK technique T1499.004 for Network Denial of Service and T1566.002 for Phishing via Social Engineering in the context of network infrastructure compromise.
Mitigation strategies for CVE-2017-10982 primarily focus on immediate software updates to FreeRADIUS version 2.2.10 or later, which includes the patched fr_dhcp_decode_options() function with proper bounds checking mechanisms. Organizations should also implement network segmentation to limit direct exposure of FreeRADIUS servers to untrusted networks, as well as deploy intrusion detection systems that can monitor for anomalous DHCP traffic patterns. Additional defensive measures include configuring firewalls to restrict DHCP traffic to trusted sources only, implementing rate limiting on DHCP packet processing, and establishing monitoring procedures to detect service disruptions. The vulnerability demonstrates the importance of proper input validation in network protocol handlers and serves as a reminder of the critical nature of maintaining up-to-date network infrastructure components. Security teams should also consider implementing automated patch management processes to ensure timely deployment of security updates across all network authentication servers to prevent exploitation of similar vulnerabilities in the future.