GHSA-44qr-rrjg-2cqq
ApostropheCMS: CAPTCHA response token not URL-encoded
Packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | @apostrophecms/form | < 1.5.5 | 1.5.5 |
| npm | @apostrophecms/login-recaptcha | < 1.2.1 | 1.2.1 |
| npm | @apostrophecms/login-hcaptcha | < 1.3.0 | 1.3.0 |
Details
As written in the advisory (Markdown source, shown as plain text).
**Summary**
Form and login CAPTCHA verification interpolate the user-supplied widget token unencoded into the server-side verification URL/body, allowing a crafted token to inject query parameters into the reCAPTCHA/hCaptcha verify request.
**Details**
- `packages/form/lib/recaptcha.js:39` — `recaptchaUri = 'https://www.google.com/recaptcha/api/siteverify?secret=${recaptchaSecret}&response=${input.recaptcha}'`
- `packages/login-recaptcha/index.js:44` — same pattern for login
- `packages/login-hcaptcha/index.js:47` — `body: 'response=${token}&secret=${secret}'`
**PoC**
```
input.recaptcha = 'attacker_token&secret=INJECTED_SECRET&something=1'
→ resulting verify URL:
https://www.google.com/recaptcha/api/siteverify?secret=<real>&response=attacker_token&secret=INJECTED_SECRET&something=1
# (replicated exactly from recaptcha.js:39)
```
**Impact**
Low: a crafted token smuggles extra `key=value` pairs (`secret`, extra `response`) into the outbound verify call, forcing verification failures (DoS of the captcha gate and of captcha-gated login/form flows) and enabling automated bypass probing; no secret exfiltration.
**Remediation** — Build the verify request with `URL` + `searchParams` (or `encodeURIComponent` on both `secret` and `response`), and validate the token against `^[A-Za-z0-9._-]{1,2048}$` before use.
References
External links from the advisory. They lead to third-party sites.
- https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-44qr-rrjg-2cqq
- https://github.com/apostrophecms/apostrophe/commit/9500b8b0e1d630d5e07fbb5fd2c25ed0943845ce
- https://github.com/apostrophecms/apostrophe/commit/f84fd41cbf6c22eb8d0008fc9c25df1f7130b350
- https://github.com/apostrophecms/apostrophe
- https://github.com/apostrophecms/apostrophe/releases/tag/@apostrophecms/[email protected]