Adminer is open-source database management software. Adminer v5.4.1 and earlier has a version check mechanism where adminer.org sends signed version info via JavaScript postMessage, which the browser then POSTs to ?script=version. This endpoint lacks origin validation and accepts POST data from any source. An attacker can POST version[] parameter which PHP converts to an array. On next page load, openssl_verify() receives this array instead of string and throws TypeError, returning HTTP 500 to all users. Upgrade to Adminer 5.4.2.

Adminer 4.8.1, when using Monolog for logging, allows a Denial of Service (memory consumption) via a crafted serialized payload (e.g., using s:1000000000), leading to a PHP Object Injection issue. Remote, unauthenticated attackers can trigger this by sending a malicious serialized object, which forces excessive memory usage, rendering Adminer’s interface unresponsive and causing a server-level DoS. While the server may recover after several minutes, multiple simultaneous requests can cause a complete crash requiring manual intervention.

Improper Access Control in Adminer versions 1.12.0 to 4.6.2 (fixed in version 4.6.3) allows an attacker to achieve Arbitrary File Read on the remote server by requesting the Adminer to connect to a remote MySQL database.

Adminer is open-source database management software. A cross-site scripting vulnerability in Adminer versions 4.6.1 to 4.8.0 affects users of MySQL, MariaDB, PgSQL and SQLite. XSS is in most cases prevented by strict CSP in all modern browsers. The only exception is when Adminer is using a `pdo_` extension to communicate with the database (it is used if the native extensions are not enabled). In browsers without CSP, Adminer versions 4.6.1 to 4.8.0 are affected. The vulnerability is patched in version 4.8.1. As workarounds, one can use a browser supporting strict CSP or enable the native PHP extensions (e.g. `mysqli`) or disable displaying PHP errors (`display_errors`).

Adminer is an open-source database management in a single PHP file. In adminer from version 4.0.0 and before 4.7.9 there is a server-side request forgery vulnerability. Users of Adminer versions bundling all drivers (e.g. `adminer.php`) are affected. This is fixed in version 4.7.9.

Adminer through 4.7.8 allows XSS via the history parameter to the default URI.

Adminer through 4.3.1 has SSRF via the server parameter.