CVE-2022-49444 is a vulnerability identified in the Linux kernel related to an out-of-bounds (OOB) memory access during the loading of kernel modules. Specifically, the flaw occurs in the handling of the section header string table size (sh_size) within the ELF module loader code. The vulnerability arises when the code checks the last character of the section header string table to verify it is a null terminator, using the condition if (info->secstrings[strhdr->sh_size - 1] != '\0'). If a maliciously crafted kernel module is loaded with a section header string table size of zero, this results in an out-of-bounds read, potentially causing a page fault and kernel crash (kernel oops). The provided kernel log snippet shows a page fault triggered by this OOB access during the insmod command execution, indicating that the vulnerability can be exploited trivially by loading a specially crafted module. This vulnerability affects multiple Linux kernel versions as indicated by the affected commit hashes. Although no known exploits in the wild have been reported yet, the vulnerability is straightforward to trigger and could be used to cause denial of service (DoS) by crashing the kernel or potentially escalate privileges if combined with other vulnerabilities. The issue was addressed by a patch that fixes the OOB access by properly validating the section header string table size before accessing it. No CVSS score has been assigned to this vulnerability yet.

For European organizations, this vulnerability poses a risk primarily as a denial-of-service vector. Since the Linux kernel is widely used across servers, cloud infrastructure, embedded systems, and desktops, an attacker with the ability to load kernel modules could cause system crashes, leading to service interruptions. This is particularly critical for organizations relying on Linux-based infrastructure for critical services such as financial institutions, healthcare providers, and government agencies. Although exploitation requires the ability to load kernel modules, which typically requires root or equivalent privileges, attackers who have already gained some level of access could leverage this vulnerability to destabilize systems or potentially facilitate privilege escalation in combination with other exploits. The lack of known exploits in the wild reduces immediate risk, but the trivial nature of the exploit means that once public, it could be weaponized quickly. The impact on confidentiality and integrity is limited unless chained with other vulnerabilities; however, availability impact is significant due to potential kernel crashes.

European organizations should prioritize applying the official Linux kernel patches that address CVE-2022-49444 as soon as they become available from their Linux distribution vendors. Until patches are applied, organizations should restrict the ability to load kernel modules to trusted administrators only and audit module loading activities closely. Employing kernel module signing and enforcing module signature verification can prevent unauthorized or malicious modules from being loaded. Additionally, implementing strict access controls and monitoring for unusual insmod or modprobe commands can help detect exploitation attempts. For environments where kernel module loading is not required, disabling module loading altogether can mitigate the risk. Organizations should also maintain up-to-date intrusion detection systems and endpoint protection solutions capable of detecting anomalous kernel module activities. Finally, thorough testing of kernel updates in staging environments before deployment is recommended to avoid unintended disruptions.