CVE-2015-8763 in FreeRADIUS
Summary
by MITRE
The EAP-PWD module in FreeRADIUS 3.0 through 3.0.8 allows remote attackers to have unspecified impact via a crafted (1) commit or (2) confirm message, which triggers an out-of-bounds read.
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Analysis
by VulDB Data Team • 09/14/2020
The vulnerability identified as CVE-2015-8763 affects the EAP-PWD module within FreeRADIUS versions 3.0 through 3.0.8, representing a critical security flaw that enables remote attackers to execute unspecified malicious actions through carefully crafted EAP commit or confirm messages. This vulnerability resides within the Extensible Authentication Protocol-Password (EAP-PWD) implementation, which is designed to provide secure password-based authentication mechanisms for network access control systems. The flaw manifests as an out-of-bounds read condition that occurs when the system processes malformed EAP-PWD messages during the authentication handshake process, specifically during the commit or confirm phases of the protocol exchange.
The technical implementation of this vulnerability stems from inadequate input validation and memory management within the EAP-PWD module's message parsing logic. When a remote attacker sends a specially crafted commit or confirm message, the system fails to properly validate the message structure and length before attempting to read data from memory locations beyond the allocated buffer boundaries. This out-of-bounds read condition can result in information disclosure, application crashes, or potentially more severe consequences depending on the specific memory corruption patterns that occur during the read operation. The vulnerability is particularly concerning because it operates at the authentication layer of network security infrastructure, where such flaws can compromise the entire authentication process and potentially provide attackers with unauthorized access to protected network resources.
The operational impact of CVE-2015-8763 extends beyond simple denial of service scenarios, as the unspecified nature of the potential consequences suggests that attackers may be able to leverage this flaw for more sophisticated attacks. The vulnerability affects organizations that rely on FreeRADIUS for network authentication services, particularly those implementing EAP-PWD for wireless network access or wired network authentication. Attackers could potentially exploit this vulnerability to extract sensitive information from memory, cause service disruption through application crashes, or potentially escalate privileges if the memory corruption leads to exploitable conditions. The remote nature of the attack means that adversaries do not require physical access to the network infrastructure and can target vulnerable systems from anywhere on the network, making this vulnerability particularly dangerous for enterprise environments.
Organizations should immediately implement mitigation strategies to address this vulnerability, beginning with upgrading to FreeRADIUS version 3.0.9 or later, which contains the necessary patches to resolve the out-of-bounds read condition. Additionally, network administrators should consider implementing network segmentation and access controls to limit exposure of vulnerable FreeRADIUS instances to untrusted networks. Monitoring for suspicious EAP-PWD message patterns and implementing intrusion detection systems that can identify malformed commit and confirm messages can help detect potential exploitation attempts. The vulnerability aligns with CWE-125, which describes out-of-bounds read conditions in software systems, and could potentially map to ATT&CK technique T1566 for initial access through credential access and T1499 for network disruption. Security teams should also conduct thorough vulnerability assessments to identify all instances of affected FreeRADIUS deployments and ensure proper patch management procedures are in place to prevent similar issues from occurring in the future.