CVE-2023-0950 is a high-severity vulnerability identified in the spreadsheet component of The Document Foundation's LibreOffice software, specifically affecting versions 7.4 prior to 7.4.6 and 7.5 prior to 7.5.1. The root cause is an improper validation of array indices (CWE-129) within the formula interpreter, particularly when processing certain malformed spreadsheet formulas such as AGGREGATE. When an attacker crafts a spreadsheet document with fewer parameters than expected by the formula interpreter, this leads to an array index underflow condition. This underflow can cause the program to access memory locations outside the intended bounds, potentially allowing an attacker to execute arbitrary code on the victim's system. The vulnerability requires the victim to open or load a maliciously crafted spreadsheet document, implying user interaction is necessary. The CVSS 3.1 base score of 7.8 reflects a high severity, with attack vector local (AV:L), low attack complexity (AC:L), no privileges required (PR:N), user interaction required (UI:R), unchanged scope (S:U), and high impact on confidentiality, integrity, and availability (C:H/I:H/A:H). Although no known exploits are currently reported in the wild, the potential for remote code execution through a widely used office suite component makes this vulnerability significant. LibreOffice is a popular open-source office productivity suite used globally, including extensively across European public administrations, educational institutions, and private enterprises, increasing the risk profile for European organizations if unpatched versions are in use.

For European organizations, the impact of CVE-2023-0950 can be substantial. LibreOffice is widely adopted in Europe due to its open-source nature, cost-effectiveness, and compatibility with various document formats. The ability for an attacker to execute arbitrary code by tricking users into opening a malicious spreadsheet could lead to full system compromise, data theft, ransomware deployment, or lateral movement within networks. Public sector entities, educational institutions, and small to medium enterprises that rely on LibreOffice without strict patch management policies are particularly vulnerable. The confidentiality of sensitive data could be breached, integrity of critical documents compromised, and availability of systems disrupted. Given the low complexity of exploitation and no need for privileges, attackers could leverage phishing campaigns to deliver malicious documents. This vulnerability could also be exploited to target critical infrastructure or strategic organizations in Europe, amplifying geopolitical risks.

European organizations should prioritize updating LibreOffice installations to versions 7.4.6 or later and 7.5.1 or later, where this vulnerability is patched. Beyond patching, organizations should implement strict document handling policies, including disabling automatic formula calculation or enabling protected view modes for documents from untrusted sources. Deploying endpoint security solutions capable of detecting anomalous behavior related to document processing can provide an additional layer of defense. User awareness training should emphasize the risks of opening unsolicited or unexpected spreadsheet files, especially those received via email. Network segmentation and application whitelisting can limit the impact of potential exploitation. For environments where immediate patching is not feasible, consider restricting LibreOffice usage or employing sandboxing techniques to isolate document processing. Monitoring for unusual process behavior or memory access patterns related to LibreOffice can help in early detection of exploitation attempts.