CVE-2022-49573 is a concurrency-related vulnerability identified in the Linux kernel's TCP stack, specifically involving the sysctl_tcp_early_retrans parameter. The vulnerability arises due to a data race condition when reading the sysctl_tcp_early_retrans variable, which can be concurrently modified by another thread or process. This lack of synchronization leads to inconsistent or corrupted reads of the variable's value. The fix implemented involves the addition of the READ_ONCE() macro to the reader of sysctl_tcp_early_retrans, ensuring atomic and consistent reads by preventing compiler optimizations that could lead to multiple memory accesses and potential race conditions. The vulnerability is rooted in the kernel's handling of TCP early retransmission settings, which are critical for network performance and reliability. Although the vulnerability does not have any known exploits in the wild as of the published date, the underlying issue could potentially lead to unpredictable kernel behavior, including data corruption or system instability, if exploited. The vulnerability affects multiple versions of the Linux kernel, as indicated by the repeated commit hash references, suggesting it is present in a range of kernel builds prior to the patch. The absence of a CVSS score and the lack of detailed exploit information imply that this is a low-level concurrency bug rather than a direct attack vector for privilege escalation or remote code execution. However, because it involves kernel-level code, any instability or corruption could have broader implications for system reliability and security.

For European organizations, the impact of CVE-2022-49573 primarily concerns system stability and reliability rather than direct data breaches or unauthorized access. Organizations relying heavily on Linux-based infrastructure, including servers, network appliances, and embedded systems, could experience kernel crashes or unpredictable TCP stack behavior if the vulnerability is triggered. This could lead to service interruptions, degraded network performance, or denial of service conditions, particularly in environments with high network traffic or concurrent configuration changes. Critical sectors such as telecommunications, finance, cloud service providers, and public administration, which often deploy Linux extensively, may face operational disruptions. While the vulnerability does not directly expose confidential data or allow remote exploitation, the potential for system instability could indirectly affect availability and integrity of services. Given the kernel-level nature of the bug, recovery from crashes or corrupted states may require system reboots or kernel updates, impacting uptime and operational continuity.

European organizations should prioritize applying the official Linux kernel patches that address CVE-2022-49573 as soon as they become available from their Linux distribution vendors. Since the vulnerability involves a race condition in kernel code, updating to a patched kernel version is the most effective mitigation. Organizations should also audit their Linux kernel versions and configurations to identify systems running vulnerable versions. For environments where immediate patching is not feasible, implementing strict change management and minimizing concurrent sysctl modifications related to TCP parameters can reduce the risk of triggering the race condition. Monitoring system logs for kernel warnings or crashes related to TCP stack operations can help detect potential exploitation or instability. Additionally, organizations should ensure robust backup and recovery procedures to mitigate the impact of any system outages caused by this vulnerability. Network segmentation and limiting administrative access to kernel parameter configurations can further reduce the risk of accidental or malicious triggering of the race condition.