CVE-2018-1130 in Linux
Summary
by MITRE
Linux kernel before version 4.16-rc7 is vulnerable to a null pointer dereference in dccp_write_xmit() function in net/dccp/output.c in that allows a local user to cause a denial of service by a number of certain crafted system calls.
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Analysis
by VulDB Data Team • 03/11/2023
The vulnerability identified as CVE-2018-1130 represents a critical null pointer dereference flaw within the Linux kernel's Datagram Congestion Control Protocol implementation. This issue affects kernel versions prior to 4.16-rc7 and resides in the dccp_write_xmit() function located in net/dccp/output.c. The vulnerability manifests when specific crafted system calls are executed by a local user, creating a scenario where the kernel attempts to dereference a null pointer during the transmission process of DCCP packets. This particular flaw falls under the CWE-476 category of Null Pointer Dereference, which is classified as a common weakness in software systems where a pointer expected to contain a valid memory address instead contains a null value.
The operational impact of this vulnerability extends beyond simple system instability, as it provides a local user with the capability to induce a denial of service condition that can severely disrupt system operations. When the vulnerable kernel function encounters the crafted system calls, the null pointer dereference causes the kernel to crash or become unresponsive, effectively rendering the affected system unavailable to legitimate users and applications. This type of vulnerability is particularly concerning in multi-user environments where unprivileged local users could exploit this weakness to degrade system performance or cause complete system hangs, potentially leading to service interruption across critical infrastructure components.
From an attacker perspective, the vulnerability requires local system access but does not necessitate elevated privileges, making it a low-barrier attack vector that can be exploited by malicious users with minimal privileges. The attack surface is limited to systems running vulnerable kernel versions and utilizing the DCCP protocol, which is less commonly deployed than TCP or UDP but still present in various network applications and services. The vulnerability aligns with ATT&CK technique T1068 by leveraging local system resources to achieve privilege escalation or system compromise, though in this case it manifests as a denial of service rather than privilege elevation. Security practitioners should note that this vulnerability demonstrates the importance of kernel-level input validation and proper error handling mechanisms, as the absence of null pointer checks in the DCCP output processing function creates an exploitable condition.
Mitigation strategies for CVE-2018-1130 primarily focus on kernel version updates and system hardening measures. The most effective remediation involves upgrading to Linux kernel version 4.16-rc7 or later, where the null pointer dereference has been addressed through proper pointer validation and error handling mechanisms. Organizations should also implement monitoring solutions to detect unusual system behavior or kernel crashes that might indicate exploitation attempts. System administrators should consider disabling DCCP protocol support if the functionality is not required, as this eliminates the attack surface entirely. Additionally, implementing proper kernel security modules and maintaining up-to-date security patches across all systems ensures comprehensive protection against similar vulnerabilities that may exist in older kernel versions. The vulnerability highlights the necessity of thorough code review processes and security testing for kernel subsystems, particularly those handling network protocol implementations where input validation is critical for system stability and security.