CVE-2012-3412 in Linux
Summary
by MITRE
The sfc (aka Solarflare Solarstorm) driver in the Linux kernel before 3.2.30 allows remote attackers to cause a denial of service (DMA descriptor consumption and network-controller outage) via crafted TCP packets that trigger a small MSS value.
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Analysis
by VulDB Data Team • 12/14/2021
The vulnerability identified as CVE-2012-3412 affects the sfc driver component within the Linux kernel version 3.2.30 and earlier, specifically targeting the Solarflare Solarstorm network interface controller family. This flaw represents a significant security concern as it enables remote attackers to execute a denial of service attack against systems utilizing affected network hardware. The vulnerability manifests through the improper handling of TCP packets that contain crafted small Maximum Segment Size (MSS) values, which creates a condition where the network controller becomes overwhelmed with DMA descriptor consumption. The Solarflare Solarstorm family of network controllers is widely deployed in enterprise environments and high-performance computing scenarios, making this vulnerability particularly impactful across various operational contexts. The flaw resides in the driver's packet processing logic where it fails to adequately validate or limit the processing of TCP segments with unusually small MSS values, leading to resource exhaustion within the network controller's descriptor rings.
The technical exploitation of this vulnerability occurs when an attacker sends specially crafted TCP packets with minimal MSS values to a target system running an affected Linux kernel version. The sfc driver processes these packets through its normal packet handling pipeline, but due to the small MSS values, the driver allocates excessive DMA descriptors to handle what appears to be a legitimate but malformed network flow. This behavior causes the DMA descriptor rings to become consumed rapidly, effectively exhausting the available resources for network packet processing. The network controller becomes unable to process additional packets, resulting in complete network service disruption for the affected system. This type of vulnerability falls under the CWE-400 category of Uncontrolled Resource Consumption, specifically representing a form of resource exhaustion attack that targets the network subsystem's descriptor management mechanisms.
The operational impact of CVE-2012-3412 extends beyond simple network disruption to potentially compromise system availability and business continuity in mission-critical environments. Organizations relying on Solarflare network controllers for high-throughput networking applications face significant risk, as the attack can be executed remotely without requiring authentication or special privileges. The denial of service condition persists until the affected system is rebooted or the network controller is manually reset, creating potential for extended service interruptions. This vulnerability particularly affects data centers, cloud environments, and enterprise networks where high-performance networking is essential, as the attack can be executed from anywhere on the network and requires minimal effort to implement. The impact is amplified in environments where network availability is paramount, such as financial services, telecommunications, and industrial control systems, where even brief network outages can result in substantial financial losses or operational disruptions.
Mitigation strategies for this vulnerability primarily involve upgrading to Linux kernel versions 3.2.30 or later, where the sfc driver has been patched to properly handle small MSS values and prevent excessive DMA descriptor consumption. System administrators should prioritize patching affected systems, particularly those running in production environments or handling sensitive network traffic. Additional mitigations include implementing network segmentation and access controls to limit exposure to potential attackers, as well as deploying intrusion detection systems that can identify and alert on anomalous TCP packet patterns that may indicate exploitation attempts. The ATT&CK framework categorizes this vulnerability under the T1499.004 technique for Network Denial of Service, and organizations should consider implementing network monitoring solutions that can detect unusual patterns in network controller resource utilization. Security teams should also establish incident response procedures specifically addressing network controller resource exhaustion attacks and maintain regular vulnerability assessments to identify other potential weaknesses in their network infrastructure. Organizations utilizing Solarflare hardware should consult with their vendors for specific patch guidance and verify that all network controllers are updated to versions that address this vulnerability.