CVE-2000-0323 is a high-severity vulnerability affecting the Microsoft Jet database engine versions 3.5, 3.51, and 4.0. This vulnerability, also known as the "Text I-ISAM" vulnerability, allows an attacker to modify text files on the affected system by crafting a specially designed database query. The Microsoft Jet engine is a database engine used primarily for accessing Microsoft Access databases and text files through ODBC or OLE DB interfaces. The vulnerability arises because the Jet engine improperly handles text file operations, enabling unauthorized modification of text files via database queries without requiring authentication. The CVSS v2 score of 7.6 reflects the network exploitable nature of the flaw (AV:N), the requirement for high attack complexity (AC:H), no authentication needed (Au:N), and complete impact on confidentiality, integrity, and availability (C:C/I:C/A:C). Exploiting this vulnerability could allow an attacker to alter critical configuration or data files, potentially leading to data corruption, unauthorized data manipulation, or denial of service. Although no known exploits are reported in the wild, the availability of patches from Microsoft (MS99-030) mitigates the risk if applied. Given the age of the vulnerability (published in 1999), it primarily affects legacy systems still running these Jet engine versions, which might be embedded in older applications or systems that have not been updated or migrated.

For European organizations, the impact of CVE-2000-0323 depends largely on the presence of legacy systems utilizing vulnerable Jet engine versions. Organizations relying on outdated Microsoft Access applications or custom software interfacing with text files via Jet could face risks of unauthorized data modification. This could compromise data integrity, leading to corrupted records, altered business-critical information, or disruption of operations relying on text file data. Confidentiality is also at risk if sensitive text files are modified to expose or manipulate data. Availability could be impacted if critical files are corrupted or deleted, causing application failures. Sectors with legacy IT infrastructure, such as government agencies, manufacturing, or financial institutions with long-standing internal applications, may be particularly vulnerable. The lack of known exploits in the wild reduces immediate risk, but unpatched systems remain exposed to potential targeted attacks or insider threats exploiting this flaw.

European organizations should conduct thorough inventories to identify any systems running Microsoft Jet engine versions 3.5, 3.51, or 4.0, especially those interfacing with text files. Immediate application of the official Microsoft patch MS99-030 is critical to remediate this vulnerability. For legacy applications that cannot be patched, organizations should consider isolating affected systems from untrusted networks to reduce exposure. Implement strict access controls and monitoring on systems handling sensitive text files to detect unauthorized modifications. Where feasible, migrate legacy applications to supported platforms or database engines that do not exhibit this vulnerability. Additionally, regular integrity checks on critical text files and database outputs can help detect tampering early. Network-level protections such as firewalls and intrusion detection systems should be tuned to detect anomalous database query patterns that might exploit this vulnerability.