CVE-2016-5244 in Solaris
Summary
by MITRE
The rds_inc_info_copy function in net/rds/recv.c in the Linux kernel through 4.6.3 does not initialize a certain structure member, which allows remote attackers to obtain sensitive information from kernel stack memory by reading an RDS message.
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Analysis
by VulDB Data Team • 05/29/2023
The vulnerability identified as CVE-2016-5244 resides within the Linux kernel's Reliable Datagram Sockets RDS (Remote Direct Memory Access) implementation, specifically in the rds_inc_info_copy function located in net/rds/recv.c. This flaw represents a classic information disclosure vulnerability that occurs due to improper initialization of kernel data structures. The RDS protocol is designed to provide low-latency, high-throughput communication between nodes in high-performance computing environments, making it a critical component in distributed systems where kernel-level security is paramount. The vulnerability affects Linux kernel versions through 4.6.3, indicating a long-standing issue that persisted across multiple releases.
The technical root cause of this vulnerability stems from the rds_inc_info_copy function failing to properly initialize a specific structure member before processing incoming RDS messages. This uninitialized memory region contains data that was previously stored in kernel stack memory, potentially including sensitive information from previous kernel operations, user-space data, or other kernel structures. When remote attackers send specially crafted RDS messages to a vulnerable system, the function reads this uninitialized memory segment and includes it in the response, effectively leaking kernel stack contents to unauthorized parties. This type of vulnerability falls under CWE-457: Use of Uninitialized Variable, which is a well-documented weakness in software development practices.
The operational impact of CVE-2016-5244 extends beyond simple information disclosure, as the leaked kernel memory could contain sensitive data such as cryptographic keys, session tokens, system credentials, or other confidential information that could be exploited by attackers. The remote nature of this vulnerability means that attackers do not require local access or authentication to exploit it, making it particularly dangerous in networked environments. This weakness creates opportunities for attackers to perform reconnaissance, gather intelligence about the target system, or potentially use the leaked information to facilitate more sophisticated attacks. The vulnerability aligns with ATT&CK technique T1005: Data from Local System, as it allows extraction of sensitive data directly from kernel memory without requiring elevated privileges or complex exploitation chains.
Mitigation strategies for CVE-2016-5244 primarily involve applying the official kernel patches released by the Linux kernel development team, which properly initialize the affected structure member before processing RDS messages. System administrators should prioritize updating their kernel versions to 4.6.4 or later, where this vulnerability has been addressed through proper memory initialization practices. Additionally, network segmentation and firewall rules can be implemented to restrict RDS traffic to trusted networks, reducing the attack surface. Monitoring for unusual RDS traffic patterns and implementing intrusion detection systems can help identify potential exploitation attempts. Organizations should also consider disabling RDS functionality if it is not required for their specific use cases, following the principle of least privilege in system configuration. The vulnerability demonstrates the critical importance of proper memory initialization in kernel space, where even seemingly minor oversights can lead to significant security implications that affect the entire system integrity.