CVE-2014-7841 in Linux
Summary
by MITRE
The sctp_process_param function in net/sctp/sm_make_chunk.c in the SCTP implementation in the Linux kernel before 3.17.4, when ASCONF is used, allows remote attackers to cause a denial of service (NULL pointer dereference and system crash) via a malformed INIT chunk.
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Analysis
by VulDB Data Team • 02/24/2022
The vulnerability identified as CVE-2014-7841 represents a critical null pointer dereference flaw within the Stream Control Transmission Protocol implementation of the Linux kernel. This vulnerability specifically affects versions prior to 3.17.4 and occurs during the processing of SCTP chunks when the ASCONF (Association Configuration) functionality is actively utilized. The SCTP protocol, defined in RFC 4960, is a reliable transport layer protocol designed to provide message-oriented communication with features including multi-homing and multi-streaming capabilities that are essential for various network applications.
The technical flaw exists within the sctp_process_param function located in the net/sctp/sm_make_chunk.c source file, which handles parameter processing during SCTP packet handling. When a malformed INIT chunk is received while ASCONF operations are active, the function fails to properly validate incoming parameters before attempting to dereference pointers that may remain uninitialized or set to NULL. This condition creates a path where malicious actors can craft specially crafted SCTP packets that trigger the null pointer dereference, leading to immediate system crash and denial of service. The vulnerability demonstrates a classic lack of input validation and proper error handling within kernel space network processing code.
The operational impact of this vulnerability extends beyond simple service disruption to encompass complete system instability and potential availability compromise for any system running affected kernel versions. Network services relying on SCTP, including but not limited to signaling protocols in telecommunications infrastructure, real-time media streaming applications, and various enterprise communication systems, become vulnerable to remote exploitation. The attack requires minimal privileges and can be executed from any network location capable of sending SCTP packets, making it particularly dangerous in network environments where SCTP is deployed. The vulnerability's exploitation directly maps to the ATT&CK technique T1499.004, which covers network denial of service attacks, and aligns with CWE-476, representing null pointer dereference in software implementations.
Mitigation strategies for CVE-2014-7841 primarily focus on immediate kernel version updates to 3.17.4 or later, which contain the necessary patches addressing the parameter validation issue. System administrators should prioritize patching affected systems, particularly those hosting network services that utilize SCTP protocols. Additional defensive measures include implementing network segmentation to limit SCTP traffic exposure, deploying firewall rules that filter malformed SCTP packets, and monitoring for unusual network traffic patterns that might indicate exploitation attempts. Organizations should also consider implementing intrusion detection systems with signature matching capabilities for SCTP-related anomalies, while maintaining regular security assessments of their network protocol implementations to identify similar vulnerabilities in other kernel components. The vulnerability highlights the importance of robust kernel space input validation and proper error handling mechanisms, particularly for protocols handling complex parameter structures in high availability network environments.