CVE-2015-8812 in Linux
Summary
by MITRE • 01/25/2023
drivers/infiniband/hw/cxgb3/iwch_cm.c in the Linux kernel before 4.5 does not properly identify error conditions, which allows remote attackers to execute arbitrary code or cause a denial of service (use-after-free) via crafted packets.
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Analysis
by VulDB Data Team • 01/25/2023
The vulnerability identified as CVE-2015-8812 resides within the Linux kernel's InfiniBand implementation, specifically in the cxgb3 driver component located at drivers/infiniband/hw/cxgb3/iwch_cm.c. This flaw represents a critical security issue that affects Linux kernel versions prior to 4.5, creating a pathway for remote attackers to exploit system resources through malformed network packets. The vulnerability stems from improper error condition handling within the kernel's communication management subsystem, which governs how InfiniBand connections are established and maintained. InfiniBand is a high-performance networking technology commonly used in data centers and high-performance computing environments, making this vulnerability particularly concerning for enterprise infrastructure.
The technical root cause of this vulnerability lies in the insufficient validation of error states during connection establishment and management processes. When the kernel receives crafted packets that trigger specific error conditions, the iwch_cm.c module fails to properly handle these scenarios, leading to a use-after-free condition where memory previously allocated to connection structures is accessed after being freed. This memory corruption vulnerability allows attackers to manipulate the kernel's memory management system, potentially executing arbitrary code with kernel-level privileges or causing system crashes through denial of service attacks. The flaw operates at the kernel level, meaning successful exploitation can compromise the entire system's integrity and availability, as the kernel maintains privileged access to all system resources.
The operational impact of CVE-2015-8812 extends beyond simple system instability, as it provides attackers with a potential path to complete system compromise. Remote exploitation means that attackers do not need physical access or local network privileges to target vulnerable systems, making this vulnerability particularly dangerous in networked environments. The use-after-free condition creates opportunities for code execution through memory corruption techniques that can be leveraged to escalate privileges, bypass security controls, or establish persistent access to compromised systems. Organizations running affected Linux kernel versions are exposed to significant risk, especially those utilizing InfiniBand networks for high-performance computing or data center operations, where the vulnerability could be exploited to disrupt critical services or gain unauthorized access to sensitive data.
Mitigation strategies for CVE-2015-8812 primarily focus on kernel version updates and network-level protections. The most effective solution involves upgrading to Linux kernel version 4.5 or later, where the error handling in the cxgb3 driver has been corrected to properly identify and manage error conditions. System administrators should also implement network segmentation and access controls to limit exposure of vulnerable systems to untrusted networks. Additional protective measures include monitoring network traffic for suspicious packet patterns and implementing intrusion detection systems that can identify potential exploitation attempts. Organizations should also consider disabling InfiniBand functionality on systems where it is not essential, as this reduces the attack surface. The vulnerability aligns with CWE-416, which describes use-after-free errors, and represents a technique commonly associated with privilege escalation attacks in the MITRE ATT&CK framework, specifically under the privilege escalation and defense evasion categories. Regular security assessments and kernel patch management programs are essential for maintaining system integrity against similar vulnerabilities.