CVE-2010-1086 in Linux
Summary
by MITRE
The ULE decapsulation functionality in drivers/media/dvb/dvb-core/dvb_net.c in dvb-core in Linux kernel 2.6.33 and earlier allows attackers to cause a denial of service (infinite loop) via a crafted MPEG2-TS frame, related to an invalid Payload Pointer ULE.
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Analysis
by VulDB Data Team • 09/07/2021
The vulnerability identified as CVE-2010-1086 represents a critical flaw in the Linux kernel's digital video broadcasting subsystem, specifically within the dvb-core module that handles DVB network operations. This issue affects kernel versions up to and including 2.6.33, where the ULE (UDP-Lite Encapsulation) decapsulation functionality contains a fundamental design flaw that can be exploited to trigger system instability. The vulnerability resides in the drivers/media/dvb/dvb-core/dvb_net.c file, which processes MPEG2-TS (MPEG-2 Transport Stream) frames for DVB network interfaces, making it a core component of digital television reception and processing capabilities in Linux systems.
The technical flaw stems from improper validation of the Payload Pointer field within ULE encapsulated packets, which is a critical element in the MPEG2-TS frame structure used for digital television transmission. When an attacker crafts a malicious MPEG2-TS frame containing an invalid Payload Pointer value, the kernel's dvb_net driver enters an infinite loop during packet processing, consuming excessive CPU resources and effectively rendering the system unresponsive. This occurs because the ULE decapsulation logic fails to properly handle malformed pointer values, causing the packet processing routine to repeatedly iterate without proper exit conditions, leading to a denial of service condition that can be triggered remotely through network-based attacks.
The operational impact of this vulnerability extends beyond simple system unavailability, as it can affect any Linux system running kernel versions prior to 2.6.34 that utilize DVB network interfaces for digital television reception or related multimedia applications. Attackers can exploit this weakness to disrupt services on set-top boxes, digital television receivers, media servers, and embedded systems that rely on Linux kernel DVB support, potentially causing widespread service interruptions in environments where continuous operation is critical. The vulnerability particularly affects systems that process incoming MPEG2-TS streams from external sources, including satellite receivers, cable TV systems, and digital media processing equipment that depend on the affected kernel components for proper operation.
This vulnerability maps directly to CWE-835, which describes the weakness of an infinite loop or similar construct that can lead to denial of service conditions, and aligns with ATT&CK technique T1499.004 for network denial of service attacks. The flaw demonstrates poor input validation practices in kernel space code, where attackers can manipulate the payload pointer field to create malformed packets that trigger the vulnerable code path. Organizations should immediately implement mitigations including kernel updates to version 2.6.34 or later, which contains the necessary patches to properly validate ULE payload pointers and prevent the infinite loop condition. Additional protective measures include network segmentation to limit exposure of DVB interfaces, implementing rate limiting on incoming MPEG2-TS traffic, and monitoring for unusual CPU utilization patterns that might indicate exploitation attempts. System administrators should also consider disabling unnecessary DVB network interfaces when not actively used and apply security patches promptly to maintain system integrity against this and similar kernel-level vulnerabilities.