SPIP before version 4.4.18 contains an unauthenticated blind SQL injection vulnerability in the public sitemap endpoint. The issue is due to the MySQL escaper function spip_mysql_cite() in ecrire/req/mysql.php returning unescaped values when the target column is a date type and the supplied value matches a pattern of a word character followed by an open parenthesis. Attackers can exploit this by supplying crafted input, such as a time-based payload through the 'annee' parameter in squelettes-dist/sitemap.xml.html, embedding arbitrary SQL into the generated query. This enables time-based and boolean-based blind SQL injection attacks that can expose arbitrary database content, including the alea_ephemere secret used to sign action nonces.

An attacker can exploit this vulnerability without authentication to perform blind SQL injection attacks against the SPIP database via the public sitemap endpoint. This can lead to unauthorized disclosure of sensitive database content, including secrets used for signing action nonces, potentially undermining the integrity of security mechanisms relying on these secrets. The vulnerability does not impact data integrity or availability directly but compromises confidentiality.

A fix is available in SPIP version 4.4.18. Users should upgrade to version 4.4.18 or later to remediate this vulnerability. No vendor advisory content was provided to indicate alternative mitigations or temporary fixes.