| Nom du plugin | Générateur de graphiques Wp |
|---|---|
| Type de vulnérabilité | XSS stocké authentifié |
| Numéro CVE | CVE-2025-8685 |
| Urgence | Faible |
| Date de publication CVE | 2025-08-11 |
| URL source | CVE-2025-8685 |
Avis de vulnérabilité : Générateur de graphiques WP (≤ 1.0.4) — XSS stocké par un contributeur authentifié via le shortcode [wpchart] (CVE‑2025‑8685)
Résumé exécutif
Cet avis décrit une vulnérabilité de script intersite stocké (XSS) dans le plugin WordPress “Générateur de graphiques WP” (versions ≤ 1.0.4), suivie sous le nom CVE‑2025‑8685. Un utilisateur authentifié avec des privilèges de contributeur (ou supérieurs) peut stocker des charges utiles malveillantes via le shortcode [wpchart] du plugin. Comme la charge utile est persistante, les visiteurs qui consultent la page affectée peuvent exécuter du JavaScript contrôlé par l'attaquant dans leurs navigateurs.
La gravité est considérée comme faible à moyenne dans la divulgation rapportée (vecteur CVSS ~6.5) car l'exploitation nécessite un compte de contributeur authentifié. Il n'y a pas de correctif officiel du fournisseur au moment de la publication. Cet avis fournit des détails techniques, des méthodes de détection, des options d'atténuation à court terme, des conseils de remédiation pour les développeurs, des exemples de règles WAF/ModSecurity, et une liste de contrôle de réponse aux incidents du point de vue d'un praticien de la sécurité expérimenté de Hong Kong.
Quelle est la vulnérabilité ?
- Logiciel affecté : Plugin Générateur de graphiques WP
- Versions affectées : ≤ 1.0.4
- Type de vulnérabilité : XSS stocké dans le rendu du shortcode [wpchart]
- Privilège requis : Contributor (ou supérieur)
- Publié : 11 août 2025
- CVE : CVE‑2025‑8685
- Correctif officiel : Aucun au moment de la publication
Le plugin rend des attributs de shortcode non fiables et/ou du contenu interne directement dans le HTML/JS front-end sans une bonne désinfection et échappement. Un contributeur peut créer du contenu avec un shortcode [wpchart] conçu contenant des fragments de script ou des gestionnaires d'événements. Lorsqu'il est rendu, le navigateur exécute le JavaScript injecté dans l'origine du site.
Pourquoi cela importe (analyse d'impact)
Le XSS stocké reste à haut risque même lorsque l'accès initial nécessite peu de privilèges. Impacts clés :
- Les charges utiles persistantes s'exécutent chaque fois que les visiteurs consultent la page, élargissant l'exposition.
- Le JavaScript exécuté s'exécute avec les privilèges d'origine de la page : il peut tenter de voler des cookies (s'ils ne sont pas HttpOnly), effectuer des actions au nom des utilisateurs connectés, afficher une interface de phishing ou rediriger les visiteurs, et charger d'autres ressources malveillantes (chaînes d'exploitation, chargeurs, cryptomineurs).
- De nombreux sites permettent des comptes de contributeurs (par exemple, blogs multi-auteurs, sites d'adhésion), donc un attaquant peut obtenir ou créer de tels comptes.
- Les comptes d'éditeur/admin visualisant le contenu front-end tout en étant connectés augmentent le risque d'escalade de privilèges ou de prise de contrôle de compte.
À quoi ressemble l'exploitation — aperçu technique de haut niveau
Le plugin enregistre un [wpchart] shortcode qui accepte des attributs (étiquettes, titres, tableaux de données, couleurs). La vulnérabilité survient lorsque ces attributs sont intégrés dans HTML ou JavaScript en ligne sans échappement contextuel.
- Un attaquant obtient ou crée un compte Contributeur.
- Ils ajoutent un article ou une page contenant un
[wpchart]shortcode avec des attributs ou un contenu interne portant des fragments de script ou des gestionnaires d'événements. - La charge utile est stockée dans la base de données. Lorsque la page est servie, le navigateur analyse le balisage ou le script injecté et l'exécute.
- Tout visiteur (y compris les éditeurs/admins connectés) peut déclencher la charge utile.
Charges utiles illustratives (ne pas déployer sur des sites publics) :
[wpchart title=""]
[wpchart data='[{"label":"
","value":10}]']
La cause profonde est le rendu d'entrées non fiables dans des contextes HTML/JS sans échappement ni validation.
Scénarios d'exploitation et qui est à risque
- Sites permettant aux contributeurs de créer du contenu (sites d'adhésion ou multi-auteurs).
- Sites avec enregistrement social, auteurs importés en masse ou contrôles de compte faibles.
- Sites où les éditeurs/admins prévisualisent ou voient le contenu frontal tout en étant authentifiés.
- Les visiteurs publics et les clients peuvent être affectés (dommages à la vie privée et à la réputation).
- Les sites de commerce sont particulièrement sensibles en raison du risque de manipulation des flux de paiement.
Détection — comment trouver des instances vulnérables ou exploitées
Rechercher des articles, des pages et des métadonnées pour [wpchart] instances et fragments de type script.
WP-CLI
# Rechercher des publications et des pages pour 'wpchart' wp post list --post_type='post,page' --format=ids | xargs -n1 -I% wp post get % --field=post_content | grep -n '\[wpchart'
SQL
-- Rechercher post_content pour le shortcode wpchart SELECT ID, post_title FROM wp_posts WHERE post_content LIKE '%[wpchart%';
Rechercher des jetons suspects : <script, onerror=, onload=, javascript :, document.cookie, fetch(, et équivalents encodés (par exemple, <script>, %3Cscript%3E).
SELECT ID, post_title, post_content FROM wp_posts WHERE post_content REGEXP '(?i)(
Also search postmeta and plugin options where chart configurations may be stored:
SELECT post_id, meta_key, meta_value
FROM wp_postmeta
WHERE meta_value LIKE '%wpchart%'
OR meta_value REGEXP '(?i)(
Examine webserver logs for POSTs creating/updating content and for outbound requests to suspicious domains originating from page views.
Short-term mitigations (site owners and admins)
If an immediate vendor patch is unavailable, take the following actions to reduce exposure:
- Remove or deactivate the plugin (preferred): If chart functionality is not required immediately, deactivate and remove the plugin until fixed.
- Restrict Contributor accounts: Temporarily disable new registrations or change default role to Subscriber. Review contributors and suspend or reset passwords for suspicious accounts.
- Review content and remove malicious shortcodes: Search posts/pages and sanitize or remove any
[wpchart]occurrences that include script-like patterns. - Temporary server-side sanitizer (virtual patch): Override the shortcode with a safe handler to sanitize attributes and content. Example mu-plugin snippet:
<?php
// mu-plugin/wpchart-sanitizer.php
if ( ! function_exists( 'wpchart_sanitized_handler' ) ) {
function wpchart_sanitized_handler( $atts = [], $content = '' ) {
// Basic attribute sanitization example
$atts = array_map( 'sanitize_text_field', (array) $atts );
// whitelist numeric attributes
if ( isset( $atts['width'] ) ) {
$atts['width'] = intval( $atts['width'] );
}
if ( isset( $atts['height'] ) ) {
$atts['height'] = intval( $atts['height'] );
}
// sanitize content using a safe allowlist
$content = wp_kses( $content, array(
'a' => array( 'href' => true, 'title' => true ),
'span' => array( 'class' => true ),
) );
// Build safe output (example: escaped)
$title = isset( $atts['title'] ) ? esc_html( $atts['title'] ) : '';
return '<div class="wpchart-safe" data-config="' . esc_attr( json_encode( $atts ) ) . '">' . $title . $content . '</div>';
}
// Remove original shortcode if registered and register safe handler
remove_shortcode( 'wpchart' );
add_shortcode( 'wpchart', 'wpchart_sanitized_handler' );
}
?>
Notes: place this as an mu-plugin so it loads early. This is a temporary mitigation to neutralize stored payloads before rendering.
- Harden browser-side controls: Implement a Content Security Policy (CSP) that blocks inline scripts and restricts script sources. Example header:
Content-Security-Policy: default-src 'self'; script-src 'self' https://trusted-cdn.example.com; object-src 'none'; base-uri 'self'; frame-ancestors 'none'Also ensure cookies use Secure and HttpOnly flags and consider SameSite settings.
- Deploy rule-based request filters: Use host-level or application-layer filters to block content submissions containing script-like payloads targeted at the
[wpchart]shortcode (examples below).
WAF / ModSecurity rules (examples)
Below are example ModSecurity rules to block common XSS patterns related to [wpchart]. Test thoroughly before applying to production.
# ModSecurity example
SecRule REQUEST_URI|REQUEST_BODY "@rx \[wpchart[^\]]*(
SecRule REQUEST_METHOD "^POST$" \
"chain, id:1001002,phase:2,deny,log,status:403,msg:'Blocked POST containing script tag',severity:2"
SecRule REQUEST_BODY "@rx <\s*script\b" "t:none"
SecRule REQUEST_BODY "@rx \[wpchart[^\]]*(onerror|onload|javascript:|document\.cookie|window\.location)" \
"id:1001003,phase:2,deny,log,status:403,msg:'Blocked suspicious attribute inside wpchart',severity:2"
SecRule REQUEST_URI "@rx /wp-admin/post.php|/wp-admin/post-new.php" \
"phase:2,id:1001004,deny,log,status:403,msg:'Blocked potential XSS payload in post content',chain"
SecRule REQUEST_BODY "@rx (onerror|onload|<\s*script|javascript:|document\.cookie|fetch\()" "t:none"
Guidance:
- Target rules narrowly (match the
[wpchart]token and plugin-specific meta keys) to reduce false positives. - Log and run in monitor/report-only mode initially to tune rules, then switch to deny once confidence is established.
- Combine with rate-limiting to mitigate repeated attempts.
Recommended permanent code fixes for plugin developers
Developers should address the root causes with robust validation and context-aware escaping:
- Sanitize input on accept: Use typed validation for numeric fields (intval(), floatval()), use
sanitize_text_field()for simple strings, and parse & validate JSON configuration server-side. - Escape output per context: Use
esc_attr()for attribute values,esc_html()for text nodes andwp_kses()with strict allowlists for any permitted HTML. Avoid echoing unchecked input into inline scripts. - Prefer data-* attributes: Emit sanitized JSON inside a data attribute via
wp_json_encode()and let a vetted client-side script consume that data safely. - Enforce capability checks and nonces: For any AJAX endpoints or admin UI that stores content, enforce
current_user_can()andcheck_admin_referer(). - Example safe shortcode output pattern:
function wpchart_safe_shortcode( $atts = [], $content = '' ) {
$atts = shortcode_atts( array(
'title' => '',
'width' => 600,
'height' => 400,
'data' => '[]',
), $atts, 'wpchart' );
// Sanitize / validate
$safe = array(
'title' => sanitize_text_field( $atts['title'] ),
'width' => intval( $atts['width'] ),
'height' => intval( $atts['height'] ),
);
// For JSON data: decode and validate structure; re-encode safely
$data = json_decode( wp_unslash( $atts['data'] ), true );
if ( ! is_array( $data ) ) {
$data = array();
}
// Validate each data point (example)
$validated_data = array();
foreach ( $data as $row ) {
$label = isset( $row['label'] ) ? sanitize_text_field( $row['label'] ) : '';
$value = isset( $row['value'] ) ? floatval( $row['value'] ) : 0;
$validated_data[] = array( 'label' => $label, 'value' => $value );
}
// Output: store config safely in data attribute and escape it for HTML
$cfg = wp_json_encode( array(
'title' => $safe['title'],
'width' => $safe['width'],
'height'=> $safe['height'],
'data' => $validated_data,
) );
return sprintf(
'<div class="wpchart" data-wpchart="%s"></div>',
esc_attr( $cfg )
);
}
Do not build inline scripts that interpolate user-provided values. Use external, audited JS that reads sanitized data-* attributes.
Incident response: If you suspect exploitation
- Take affected page(s) offline (unpublish) or put the site into maintenance mode if widespread.
- Identify and remove malicious posts, shortcodes or plugin meta entries (see detection section).
- Change passwords for Contributor+ accounts and administrators. Consider forcing password resets for all users if compromise is suspected.
- Inspect server logs for suspicious activity and block attacker IPs at host or WAF level.
- Run a full malware scan and file integrity check. Look for added admin users, unexpected scheduled tasks, or backdoors.
- Rotate API keys, integration tokens, and any stored credentials that could be exposed.
- If admin accounts were compromised, audit site settings and restore from a known-clean backup if necessary.
- Notify affected users if user data may have been exposed, following applicable privacy and breach-notification law.
- After cleanup, re-enable stricter registration policies, enforce two-factor authentication for elevated roles, apply CSP and secure HTTP headers.
- Monitor for re-injection attempts and maintain long-term detection rules.
Monitoring and detection after cleanup
- Enable logging for request filters and review blocked events.
- Set up content integrity checks to detect reappearance of suspicious
[wpchart]shortcodes or injected script tags. - Schedule weekly scans and manual reviews for a period after the incident.
- Deploy updates in a staging environment and validate fixes before production rollout.
Hardening recommendations to reduce XSS risk site-wide
- Apply principle of least privilege: limit Contributor role usage and consider custom roles with reduced capabilities.
- Require editorial review workflows: contributors should submit for review rather than publish directly.
- Enforce strong passwords and two-factor authentication for editors and administrators.
- Restrict untrusted user registration or require administrator approval.
- Use CSP in report-only mode first to identify issues, then enforce once safe.
- Ensure session cookies are HttpOnly and Secure; consider SameSite settings.
- Keep WordPress core and plugins updated and perform periodic security audits.
A short note for developers: test for XSS during QA
- Include input fuzzing for shortcode attributes and stored values.
- Automate tests to detect unescaped outputs in HTML and JS contexts.
- Review third-party chart libraries and ensure data is passed safely (prefer data-* + JSON + validated client-side rendering).
- Maintain a clear disclosure policy and a public changelog to accelerate coordinated fixes when issues are reported.
Frequently asked questions (FAQ)
Q: If I am not using the WP Chart Generator plugin, am I affected?
No. This advisory concerns specifically the WP Chart Generator plugin (≤ 1.0.4). However, the general guidance applies to any plugin that renders unescaped user input.
Q: If an attacker needs a Contributor account, is my site safe?
Not necessarily. Many sites allow registrations that map to low-privilege roles; weak or reused passwords are a common vector. Treat user registration as a potential risk and limit privileges where possible.
Q: Will a Content Security Policy fully prevent exploitation?
A properly configured CSP substantially reduces the impact of many XSS payloads by blocking inline scripts and restricting script origins, but CSP should complement input sanitization and server-side protections — it is not a substitute for correct coding.
Q: Is the issue already patched?
At the time of this advisory, no official patched release was available. Follow the plugin's release channel for updates and apply the mitigations listed here until a patch is published.
Closing thoughts
Stored XSS like CVE‑2025‑8685 can have persistent and far-reaching consequences. Although exploitation requires authenticated access, many realistic paths exist to obtain contributor-level permissions. Treat unescaped shortcode attributes and plugin-rendered client-side scripts as high priority. Immediate actions: review and sanitize content, restrict Contributor capabilities, apply temporary sanitization or request-filtering, and consider deactivating the plugin until it is fixed. Plugin authors should implement strict input validation and context-aware escaping for all shortcode attributes and stored content.
If you lack in-house capability to perform scans or apply mitigations, engage a trusted security practitioner or managed service to assist with detection, virtual patching and recovery steps. Maintain careful logs of remediation actions and preserve forensic artifacts if a compromise is suspected.
Stay vigilant. Review user-generated content regularly and reduce the blast radius of low-privilege user accounts.