CVE-2024-49944 is a vulnerability identified in the Linux kernel's SCTP (Stream Control Transmission Protocol) implementation. The issue arises in the function sctp_listen_start(), which is invoked by sctp_inet_listen(). When the SCTP autobind operation (sctp_autobind()) fails, the kernel should reset the socket state (sk_state) back to CLOSED. However, due to this flaw, the state remains as LISTENING. This improper state management leads to a null pointer dereference when the socket option SCTP_REUSE_PORT is set and sctp_inet_listen() is called again. Specifically, the bind_hash pointer is dereferenced while being NULL, causing a kernel crash. The crash is confirmed by Kernel Address Sanitizer (KASAN) reports indicating a null pointer dereference at net/sctp/socket.c line 8617. The vulnerability affects multiple versions of the Linux kernel, as indicated by the repeated commit hashes, and was published on October 21, 2024. No known exploits are currently reported in the wild. The vulnerability can cause denial of service (DoS) by crashing the kernel, impacting system availability. The flaw is rooted in improper error handling and state management within the SCTP networking stack, which is used for reliable, message-oriented communication in some networked applications. Since SCTP is less commonly used than TCP or UDP but is critical in certain telecom and signaling applications, the impact depends on the deployment context. No CVSS score is assigned yet, and no patches or exploit code links are provided in the data, though the issue is acknowledged and published by the Linux project.

For European organizations, the primary impact of CVE-2024-49944 is the potential for denial of service due to kernel crashes on systems running vulnerable Linux kernels with SCTP enabled. This can disrupt critical services, especially in telecom infrastructure, financial services, and industrial control systems that rely on SCTP for signaling or communication. Organizations using Linux servers in data centers, cloud environments, or embedded systems that utilize SCTP may experience unexpected downtime or require system reboots to recover. The vulnerability does not appear to allow privilege escalation or remote code execution directly but can be triggered by local or remote SCTP socket operations, potentially by an attacker with network access or local user privileges. Given the widespread use of Linux in European IT infrastructure, especially in telecom and enterprise environments, the risk is notable. However, the lack of known exploits and the requirement for specific SCTP configurations reduce the immediate threat level. Still, unpatched systems remain vulnerable to crashes, which could be exploited for targeted disruption or as part of a larger attack chain.

European organizations should prioritize updating Linux kernels to versions where this vulnerability is patched once official updates are released. Until patches are available, administrators should consider disabling SCTP support if it is not required, as this will eliminate the attack surface related to this vulnerability. For systems that must use SCTP, monitoring kernel logs for crashes or anomalies related to SCTP socket operations can provide early warning signs. Network segmentation and firewall rules should restrict SCTP traffic to trusted sources to reduce exposure. Additionally, review and restrict the use of the SCTP_REUSE_PORT socket option in applications, as it is involved in the vulnerability trigger. Employing kernel hardening techniques and enabling KASAN or similar runtime protections in testing environments can help detect and analyze potential exploitation attempts. Finally, maintain robust incident response plans to quickly recover from potential denial of service incidents caused by this vulnerability.