| Package | Affected versions | Patched versions |
|---|---|---|
| phpmyfaq/phpmyfaq | < 4.1.1 | 4.1.1 |
| thorsten/phpmyfaq | < 4.1.1 | 4.1.1 |
| phpmyfaq | < 4.1.1 | 4.1.1 |
An unauthenticated attacker can submit a guest FAQ with an email address that is syntactically valid per RFC 5321 (quoted local part) yet contains raw HTML — for example "<script>alert(1)</script>"@evil.com. PHP's FILTER_VALIDATE_EMAIL accepts this email as valid. The email is stored in the database without HTML sanitization and later rendered in the admin FAQ editor template using Twig's |raw filter, which bypasses auto-escaping entirely.
phpmyfaq/src/phpMyFAQ/Controller/Frontend/Api/FaqController.php:99 $email = trim((string) Filter::filterVar($data->email, FILTER_VALIDATE_EMAIL)); PHP accepts "<script>alert(1)</script>"@evil.com as a valid email (RFC 5321 allows <, > inside quoted local parts). Confirmed: "<script>alert(1)</script>"@evil.com => string (valid, not false)
phpmyfaq/src/phpMyFAQ/Faq.php — email retrieved directly as $row->email from the database.
phpmyfaq/assets/templates/admin/content/faq.editor.twig:296 <input type="email" name="email" id="email" value="{{ faqData['email'] | raw }}" class="form-control">
Affected version: 4.2.0-alpha, commit f0dc86c8f
The reproduction of the vulnerability was implemented with the help of AI while reviewing the source code to generate the proof-of-concept. Please kindly note this for reference. Since the vulnerability has already been confirmed directly in the source code, the proof-of-concept code may be considered as a reference only.
Please extract the attached compressed file and proceed. poc.zip
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Scan my site freeWhen an administrator opens /admin/faq/edit/{id}/{lang} to review the pending FAQ, the injected script executes in the admin's browser context. This allows an attacker to:
The attack chain requires no authentication. By default, records.allowNewFaqsForGuests=true allows unauthenticated FAQ submission, and records.defaultActivation=false guarantees the administrator must visit the edit page to review it.
Note on captcha: The built-in captcha is enabled by default when the PHP gd extension is present (spam.enableCaptchaCode=true). This prevents fully automated exploitation but does not prevent a targeted manual attack — an attacker can solve the captcha once and submit the payload.
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