CVE-2014-3953 in FreeBSD
Summary
by MITRE
FreeBSD 8.4 before p14, 9.1 before p17, 9.2 before p10, and 10.0 before p7 does not properly initialize certain data structures, which allows local users to obtain sensitive information from kernel memory via a (1) SCTP_SNDRCV, (2) SCTP_EXTRCV, or (3) SCTP_RCVINFO SCTP cmsg or a (4) SCTP_PEER_ADDR_CHANGE, (5) SCTP_REMOTE_ERROR, or (6) SCTP_AUTHENTICATION_EVENT notification.
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Analysis
by VulDB Data Team • 02/08/2022
This vulnerability resides in the Stream Control Transmission Protocol implementation within FreeBSD operating systems across multiple versions including 8.4 before patch 14, 9.1 before patch 17, 9.2 before patch 10, and 10.0 before patch 7. The flaw represents a classic information disclosure issue where kernel memory contents are inadvertently exposed to local users due to improper initialization of data structures. The vulnerability specifically affects SCTP control messages and notifications that are used for communication between applications and the kernel's SCTP implementation. When applications send or receive SCTP messages through the socket interface, certain control message types and notification events fail to properly initialize memory structures before being populated with kernel data. This incomplete initialization creates a situation where sensitive kernel memory contents, potentially including credentials, cryptographic keys, or other confidential information, may be accessible through the control message interfaces.
The technical execution of this vulnerability occurs through specific SCTP socket operations that handle control messages and notifications. Attackers can exploit this by crafting specific socket operations that trigger the use of uninitialized memory structures within the kernel's SCTP implementation. The vulnerability manifests when applications make system calls such as sendmsg or recvmsg with SCTP control messages including SCTP_SNDRCV, SCTP_EXTRCV, or SCTP_RCVINFO control messages, or when handling SCTP notifications such as SCTP_PEER_ADDR_CHANGE, SCTP_REMOTE_ERROR, or SCTP_AUTHENTICATION_EVENT events. These operations access kernel memory structures that have not been properly initialized, allowing local users to read kernel memory contents that should remain confidential. The flaw is particularly concerning because it enables information disclosure without requiring elevated privileges, as the vulnerability exists within the kernel's handling of legitimate socket operations. This represents a violation of the principle of least privilege and demonstrates a failure in kernel memory management.
The operational impact of this vulnerability is significant for FreeBSD systems running the affected versions, as it allows local attackers to potentially extract sensitive kernel information that could be used for further exploitation. The disclosed information might include cryptographic keys, credential data, or other confidential kernel structures that could aid in privilege escalation attacks or system compromise. Attackers could potentially use this information to construct more sophisticated attacks or to bypass security controls. The vulnerability affects systems where SCTP is actively used or where applications may interact with SCTP socket operations, making it particularly relevant for systems that handle network communications through the SCTP protocol. The impact extends beyond simple information disclosure as the leaked kernel memory could contain pointers, system configuration data, or other information that could be leveraged in subsequent attacks.
This vulnerability aligns with CWE-126, which describes "Buffer Over-read" conditions where data is read past the end of a buffer, and specifically relates to improper initialization of memory structures. The flaw also connects to the broader category of memory safety issues that have been addressed through various security frameworks and standards. From an ATT&CK perspective, this vulnerability could be categorized under T1068, which covers "Exploitation for Privilege Escalation" and T1083, "File and Directory Discovery," as the information disclosure could enable further reconnaissance and exploitation activities. The vulnerability demonstrates the importance of proper memory initialization in kernel code and highlights the need for comprehensive security testing of system call interfaces. Organizations should prioritize applying the relevant patches for their FreeBSD systems to address this vulnerability, as the risk of exploitation increases with the exposure time. Additionally, system administrators should monitor for potential exploitation attempts and consider implementing network segmentation to limit the attack surface for systems where SCTP is not actively required. The vulnerability underscores the critical importance of maintaining up-to-date system patches and implementing proper kernel security measures to prevent unauthorized access to sensitive kernel memory contents.