插件名称	RingCentral Communications
漏洞类型	Missing server-side verification
CVE 编号	CVE-2025-7955
急	批判的
CVE 发布日期	2025-08-28
源网址	CVE-2025-7955

Urgent: RingCentral Communications Plugin (v1.5–1.6.8) — 2FA Authentication Bypass (CVE-2025-7955) — What WordPress Site Owners Must Do Now

日期： 28 August 2025
嚴重程度： High / CVSS 9.8
Affected plugin: RingCentral Communications (WordPress) — versions 1.5 through 1.6.8
已修復： 1.7.0
CVE: CVE-2025-7955

We’re the WP‑Firewall security team. We research and protect WordPress sites every day. Today we’re publishing an operational, no‑fluff breakdown of a dangerous vulnerability found in the RingCentral Communications plugin that impacts sites running versions 1.5 through 1.6.8. The vulnerability allows attackers to bypass server‑side verification of a 2FA step (via the ringcentral_admin_login_2fa_verify function). When left unpatched, it can enable unauthorized privilege escalation and full site takeover.

This post explains what the bug is, how attackers will likely exploit it in the wild (without providing exploit code), how to detect attempts and compromise, immediate risk mitigation steps, and long‑term developer and operational fixes — including how WP‑Firewall can protect your site right now if you cannot immediately update.

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Executive summary (short)

• The plugin had a missing server‑side verification in the 2FA verification path (function ringcentral_admin_login_2fa_verify), allowing attackers to bypass authentication and obtain admin‑level access under certain conditions.
• A patch is available in RingCentral Communications 1.7.0 — updating is the single best remediation.
• If you cannot patch immediately, virtual patching via a WAF and hardening steps will materially reduce risk. WP‑Firewall can deploy protections that block exploit attempts for you in minutes.
• If you’re an admin of a site running a vulnerable version, assume compromise is possible and follow the recovery checklist below.

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Background: what the plugin does and why this matters

The RingCentral Communications plugin integrates WordPress dashboards with RingCentral telephony/communications services. It commonly handles account linking, session exchanges, and admin flows that require authentication and sometimes 2‑factor verification (for example, during administrative login flows or when linking accounts).

Because the plugin handles an authentication flow and interacts with external authentication tokens, any failure to perform reliable server‑side checks (nonce, capability, session validation, or API token exchange) can be catastrophic: an attacker can abuse endpoints intended for legitimate 2FA exchanges to bypass access controls.

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Technical root cause (high level)

The vulnerability was introduced by insufficient server‑side verification in the 2FA verification endpoint. In practical terms:

• The function ringcentral_admin_login_2fa_verify accepted input and returned success/failure without enforcing one or more of the following:
  • Proper authenticated session checks (is the request linked to a valid, logged‑in user?)
  • Proper capability checks (current_user_can or equivalent)
  • A valid WordPress nonce via check_ajax_referer or equivalent
  • A secure server‑side exchange/validation with RingCentral (verifying that the token was indeed issued for the requesting session)
• Because the server trusted client input or lacked robust verification, callers could trick the application into believing the 2FA step succeeded.

This is classic Broken Authentication: the server failed to verify the identity assertion in a manner that can’t be forged by an attacker.

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Realistic attacker scenarios

• Automated scanners look for the vulnerable endpoint (admin‑ajax action or direct plugin handler) and send crafted POSTs to simulate successful 2FA. If the plugin incorrectly flags success, the attacker escalates to an authenticated admin session or bypasses an admin lockout.
• Opportunistic attackers scrape plugin versions across many WordPress sites and attempt the same request pattern at scale, looking for hits. Because the endpoint is part of a plugin and not protected by core WordPress checks, mass exploitation is feasible.
• If successful, the attacker can create an admin user, inject a backdoor, modify plugin options (including API credentials used to talk to RingCentral), exfiltrate data, or install additional malicious plugins/themes.

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影響

• Site takeover: Admin privileges allow full site control.
• Data exposure: Messages, integrated phone data, or any data the plugin stores can be exposed.
• Credential theft: Stored tokens or API credentials could be exfiltrated.
• Persistent backdoors: Attackers commonly install persistent backdoors to maintain access after remediation.
• Reputation and business risk: For businesses using RingCentral integrations, this can be especially damaging if customer call data or phone integrations are impacted.

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Indicators of Compromise (IoCs) — What to look for now

If your site runs a vulnerable version, investigate the following immediately:

• New or unexpected administrator accounts created around or after 28 Aug 2025.
• Successful admin logins from unknown IP addresses (check wp_用戶 and login logs).
• Suspicious POST requests to these endpoints (or similar) in your server logs:
  • admin‑ajax.php?action=ringcentral_admin_login_2fa_verify
  • Any direct plugin endpoint that references ringcentral or 2fa_verify
• Modified plugin files or new plugin/theme files that you did not install.
• Outbound connections initiated by WordPress or PHP processes to unusual external hosts.
• Unexpected option changes in the wp_選項 table (especially entries related to ringcentral, API tokens, or plugin settings).
• Cron tasks (wp_cron jobs) that were added without authorization.

Collect logs now — save access logs, PHP error logs, and database activity — in case you need to audit or perform forensic analysis.

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Detection: simple queries and logs to check

• Check plugin version via the wp-admin plugins page or via WP‑CLI:

wp plugin get rccp-free --field=version

• Search access logs for suspicious POSTs (example grep):

grep "ringcentral_admin_login_2fa_verify" /var/log/apache2/*access.log*

• Look for newly created admin users:

SELECT ID,user_login,user_email,user_registered FROM wp_users
JOIN wp_usermeta ON wp_users.ID = wp_usermeta.user_id
WHERE wp_usermeta.meta_key = 'wp_capabilities' AND wp_usermeta.meta_value LIKE '%administrator%';

• Monitor authentication failures followed by success for the same IP address.

Do not attempt to exploit or craft requests to verify vulnerability — that could put you in legal trouble or further compromise your environment. Instead, use the safe detection guidance above.

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Immediate mitigation steps (if you are running a vulnerable version)

1. UPDATE (preferred)
   Upgrade the plugin to version 1.7.0 or later immediately. This is the proper fix. Always update on a staging site first if you depend on customizations, but prioritize security.
2. TEMPORARY DISABLE (if you cannot update)
   If you cannot update right now, deactivate the plugin. Deactivation removes the exposed endpoints and prevents remote abuse.
3. VIRTUAL PATCHING (fastest mitigation when you cannot update)
   Apply a WAF rule that blocks requests to the vulnerable function/action unless they originate from trusted internal IPs or authenticated sessions. If you use WP‑Firewall, enable the automatic virtual patch for this vulnerability now — it will block known exploit patterns within minutes.
4. LIMIT ACCESS TO admin‑ajax (surgically)
   If the plugin uses admin‑ajax.php?action=... you can block POST requests matching that action parameter via webserver or WAF rules (see example ModSecurity rule below).
5. HARDEN ADMIN
   Force a password reset for all administrators and ensure 2FA is enforced for all admin accounts (via a separate, well‑tested plugin or core MFA).
6. ROTATE CREDENTIALS
   Rotate any API credentials or tokens used by the plugin and review third‑party integrations.
7. AUDIT & CLEANUP
   Scan for suspicious files and changed timestamps; check for backdoors; run a full malware scan and consider professional incident response if you find indicators of active compromise.

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Recommended immediate checklist (copyable for operations teams)

• [ ] Verify plugin version on every site: deprecate 1.5–1.6.8
• [ ] Upgrade to 1.7.0 as first step
• [ ] If upgrade is delayed, disable the plugin on public sites
• [ ] Enable WP‑Firewall virtual patch for RingCentral exploit signatures
• [ ] Force password reset for all admin users
• [ ] Enforce MFA for all privileged users
• [ ] Rotate plugin API keys (RingCentral tokens) and secrets
• [ ] Export and archive server logs for forensic analysis
• [ ] Scan site files for unknown PHP files or recent modifications
• [ ] If signs of compromise exist, engage incident response

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How WP‑Firewall defends you (virtual patching & WAF rules)

We understand that in enterprise or large multi‑site environments, immediate plugin updates sometimes take time. WP‑Firewall gives you three layers of protection you can deploy immediately:

1. Virtual patching (rule deployment)
   Our research team creates a server‑side rule that blocks the specific request patterns used to reach the vulnerable ringcentral_admin_login_2fa_verify path. These rules prevent the exploit payload from reaching the vulnerable function regardless of whether the plugin has been updated.
2. Granular WAF signatures and rate limiting
   We deploy signatures that watch for action=ringcentral_admin_login_2fa_verify (and similar plugin endpoints) and enforce:
   – Block for unauthenticated requests
   – Rate limit to prevent bruteforce/scanner noise
   – Geo/IP or reputation based blocking for noisy sources
3. Attack mitigation + monitoring
   Alerts for suspicious traffic patterns, automatic blocking of IPs showing exploit behavior, and integration with your security dashboard for incident triage.

Below is a conceptual WAF rule example you can implement in ModSecurity (or ask your host to implement). This rule denies POST requests containing the vulnerable action unless the request contains a valid WP authentication cookie. This is a defensive pattern — it blocks unauthenticated requests attempting to call the vulnerable action.

Note: This example is illustrative; adapt it to your environment and test in a staging environment before production.

# Example ModSecurity rule (illustrative):
SecRule REQUEST_METHOD "POST" "phase:2,chain,id:1009001,deny,status:403,msg:'Block ringcentral_admin_login_2fa_verify unauthenticated POST'
  SecRule &ARGS:action "@eq 1" "chain"
  SecRule ARGS:action "@rx ^ringcentral_admin_login_2fa_verify$" "chain"
  SecRule &REQUEST_COOKIES:wordpress_logged_in_* "@lt 1""

Alternatively, a simple .htaccess block that denies access to admin‑ajax POSTs with that action (be careful — test before deployment):

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteCond %{REQUEST_METHOD} POST
RewriteCond %{QUERY_STRING} action=ringcentral_admin_login_2fa_verify [NC]
RewriteRule ^wp-admin/admin-ajax.php - [F,L]
</IfModule>

重要： admin‑ajax is used by many legitimate plugins. A blanket block may break functionality. Use targeted WAF rules or virtual patching that differentiates authenticated vs unauthenticated calls.

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Developer remediation guidance (for plugin authors / maintainers)

If you maintain the plugin or contribute code, here are the concrete fixes and hardening steps you must implement and test:

1. Enforce server‑side capability checks
   使用 當前使用者能夠（） to verify that the requester has the expected capabilities. Don’t rely on client‑side assertions or parameters.
2. Use WP AJAX nonces
   使用 檢查_ajax_referer() to validate a nonce for any sensitive admin AJAX action. Nonces are not a panacea but are an important server‑side anti‑CSRF control.
3. Validate sessions and tie verification to server state
   The 2FA verification response from an external provider should be bound to a server‑stored session (or ephemeral DB entry) and validated against the provider’s response server‑to‑server. Do not accept a simple client boolean or token without a server‑side exchange.
4. Proper error handling and logging
   Log all failed and successful 2FA attempts, with IP and context, to allow auditing.
5. Rate limit sensitive endpoints
   Implement rate limiting or back‑off logic to make automated exploitation harder.
6. Unit and integration tests
   Add automated tests: ensure 2FA verification only succeeds when preceding steps were completed and stored on server state, and ensure unauthenticated requests are rejected.
7. Release notes and coordinated disclosure
   Communicate the fix clearly to admins and provide upgrade guidance.

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Post‑incident cleanup and recovery

If you discover indicators of compromise, do the following:

• Snapshot current site files and databases for forensic analysis.
• Put the site into maintenance mode or a read‑only state as needed.
• Rotate all passwords for administrator accounts and external integrations (RingCentral API keys, OAuth tokens).
• Reinstall WordPress core and plugins from trusted sources (or restore from a clean backup made before compromise).
• Search for persistent backdoors in uploads, themes, and mu‑plugins directories. Check wp-config.php for unauthorized modifications.
• Reissue any compromised certificates/credentials used by the site.
• Inform stakeholders and follow privacy/incident disclosure policies required by law or contracts.
• After cleanup, reinstate logs and monitoring; enable enhanced WAF protections and monitoring to detect re‑attempts.

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Hardening checklist to reduce risk from plugin vulnerabilities generally

• Keep plugins/themes updated — apply security patches quickly.
• Run a managed WAF that supports quick virtual patching.
• Enforce MFA for all admin accounts.
• Limit number of admin users and use least‑privilege principles.
• Use a separate admin IP allowlist or restrict wp‑admin (where possible).
• Monitor logs (failed logins, new admin creation, suspicious admin ajax calls).
• Back up regularly and test restore procedures.
• Use role separation for day‑to‑day site maintenance vs critical admin tasks.

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Why virtual patching matters (and how WP‑Firewall helps)

In real operations, patching can be delayed: plugin customizations, staging workflows, regulatory processes, or large multisite operations can slow deployments. Virtual patching fills that gap:

• It enforces a server‑side rule set that blocks exploit attempts before they reach the vulnerable code.
• It buys you time to test and deploy a proper patch.
• It reduces risk immediately across all sites we protect.

When we detect a vulnerability like this in popular plugins, our research and protection teams prepare and deploy virtual patch rules targeted at the exact exploit vectors. These rules are designed to minimize collateral impact while stopping malicious traffic.

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Why this matters now:

• Virtual patching deployed to cover the RingCentral exploit can be enabled immediately for protected sites.
• You get automatic WAF rules and malware scans without needing to change plugin code or turn sites off.
• The free plan is enough to block the common exploitation patterns for this issue; upgrade options are available for extra remediation and ongoing expert services.

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Long term: operational best practices for agencies and enterprise

• Integrate vulnerability scanning and inventory into CI/CD pipelines.
• Maintain a quick‑reaction security release path for plugin/theme changes.
• Use a staged rollout for updates, combined with accelerated emergency patching for critical fixes.
• Contract with a trusted managed WAF provider (or run your own hardened edge) to ensure virtual patching is available.
• Keep a regularly audited inventory of all plugins and versions deployed across environments.

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Final recommendations — immediate actions (critical)

If you manage a WordPress site with RingCentral Communications plugin versions 1.5–1.6.8:

1. Verify plugin version now.
2. If you can, update to 1.7.0 immediately.
3. If not, disable the plugin until update is possible.
4. Enable WP‑Firewall virtual patching or an equivalent WAF rule to block exploit traffic now.
5. Force admin password rotation and verify all admin accounts.
6. Rotate RingCentral and other integration credentials.
7. Archive and preserve logs for possible forensic analysis.
8. If you see evidence of compromise, engage a security incident responder.

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Closing thoughts from WP‑Firewall

This vulnerability is serious because it targets authentication — the gatekeeper for everything on your site. Our advice is straightforward: update if you can; if you cannot, protect with a virtual patching WAF immediately and assume heightened risk until protections are in place.

If you want our team to review your site, enable automated protection, or deploy a virtual patch for the RingCentral vulnerability, start with our free WP‑Firewall Basic plan and follow up from your dashboard. You’ll get managed firewall coverage and immediate rule deployment while you plan the plugin update.

Stay safe, check your sites, and reach out to our team if you need help implementing the steps above.

— The WP‑Firewall Research & Response Team