Rough sketch of a password reset for eXist-db

pw-reset.xq

xquery version '3.1';
(:~
  this script must be run with a user in the DBA group
  
  add this line to your post-install script or run it manually
  it will set the GID sticky bit
  chown('/path/to/this/script.xq', 'admin', 'dba')
  chmod('/path/to/this/script.xq', 'rwxr-S---')
:)

(:~
 do some checks on the password
:)
declare function local:pass-ok($password) {
  string-length($password) > 11
};

declare variable $local:user := request:get-parameter('user', '')
declare variable $local:pass := request:get-parameter('pass', '')

(: check if user exists and new password is good :)
if (
  sm:user-exists($local:user) and
  local:pass-ok($local:pass)
)
then (sm:passwd($local:user, $local:pass))
else ('ERROR')