CVE-2024-10977 is a vulnerability in PostgreSQL where the client library libpq can be misled by server error messages if the server is not fully trusted under current SSL or GSSAPI authentication settings. Specifically, a malicious or man-in-the-middle attacker can send crafted error messages containing arbitrary non-NUL bytes. These bytes can be interpreted by libpq clients, such as the psql command-line tool, as legitimate query results rather than error messages. This occurs because some client interfaces do not clearly demarcate error message boundaries from query output, potentially causing users or automated screen-scrapers to misinterpret error data as valid information. The vulnerability affects PostgreSQL versions before 17.1, 16.5, 15.9, 14.14, 13.17, and 12.21. The attack vector requires network access (AV:N), has high complexity (AC:H), does not require privileges (PR:N), but does require user interaction (UI:R). The impact is limited to integrity, as it can cause incorrect data interpretation but does not expose confidential data or cause denial of service. No known exploits have been reported in the wild, and PostgreSQL maintainers have released patches in the specified versions to address this issue.

For European organizations, the primary impact of CVE-2024-10977 is the potential for data integrity issues where error messages might be misinterpreted as valid query results. This could lead to incorrect decision-making or automated processes acting on false data, especially in environments where database query results are consumed by scripts or screen-scrapers without robust error handling. While confidentiality and availability are not directly affected, the integrity compromise could have downstream effects in sectors relying heavily on accurate database outputs, such as finance, healthcare, and critical infrastructure. The requirement for a man-in-the-middle position and user interaction limits the likelihood of widespread exploitation, but organizations with less secure network configurations or insufficient client-side validation are at higher risk. The absence of known exploits reduces immediate threat levels but does not eliminate future risk.

European organizations should promptly upgrade PostgreSQL installations to the fixed versions: 17.1, 16.5, 15.9, 14.14, 13.17, or 12.21. Network security should be enhanced to prevent man-in-the-middle attacks, including enforcing strict SSL/TLS configurations and validating server certificates rigorously. Client applications using libpq should be audited to ensure they clearly distinguish error messages from query results, possibly by updating client software or adding explicit parsing logic. Implementing network segmentation and monitoring for unusual error message patterns can help detect attempted exploitation. Additionally, educating users and administrators about the risks of interpreting error messages as valid data can reduce the impact of potential attacks. Regular vulnerability scanning and patch management processes should be enforced to maintain updated PostgreSQL versions.