插件名称	YourMembership Single Sign On
漏洞类型	未经身份验证的访问
CVE 编号	CVE-2025-10648
急	低的
CVE 发布日期	2025-10-15
源网址	CVE-2025-10648

Critical advisory: YourMembership Single Sign On (YM SSO Login) plugin (<= 1.1.7) — Missing authorization allows unauthenticated sensitive information exposure (CVE-2025-10648)

已发布: 15 October 2025
作者： WP‑Firewall Security Team

Note: This advisory is written from the perspective of WP‑Firewall, a WordPress security provider and WAF vendor. Our goal is to explain the risk, show how attackers can misuse the issue at a high level, and — most importantly — provide practical, actionable mitigations you can apply immediately to protect your sites.

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Executive summary

A broken access control vulnerability (CVE-2025-10648) has been disclosed in the “Login with YourMembership – YM SSO Login” WordPress plugin (versions up to and including 1.1.7). The vulnerability stems from a function that exposes “test attributes” without proper authorization checks. An unauthenticated attacker can trigger that function and retrieve information that should not be publicly visible.

Although the reported CVSS score is moderate (5.3), the context matters — the exposed data could include internal identifiers, SSO-related attributes, debug/test configuration and other details that help an attacker enumerate and prepare follow‑on attacks (targeted credential stuffing, SSO abuse, targeted phishing, or privilege escalation). At the time of reporting there is no official patch available from the plugin author.

If you run sites using this plugin, treat this as a priority for investigation and mitigation. The safest approaches are: remove or disable the vulnerable plugin, block the vulnerable endpoint/action with your WAF, or otherwise restrict access to it until an official patch is released.

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What is the vulnerability?

• Vulnerability type: Broken Access Control / Missing Authorization (OWASP A05)
• Affected component: “moym_display_test_attributes” (a function/action used by the plugin)
• 受影响的版本： YM SSO Login plugin <= 1.1.7
• 所需权限： 未经身份验证
• Public identifier: CVE-2025-10648

In short, a plugin function that should only respond to privileged or authenticated requests does not perform proper authorization checks. The function returns internal “test attributes” to the caller. Because authentication/authorization were not enforced, any unauthenticated visitor (or automated scanner) can request and receive those attributes.

What the “test attributes” include was not exhaustively enumerated in the public report, but similar disclosures of this type commonly reveal:

• Internal or debug tokens and flags
• Member or user identifiers
• Internal configuration values and endpoints
• Partial SSO configuration or mapping data
• Error messages and stack traces that leak environment details

Even when the exposed information seems “non-sensitive” at first glance, it often provides an attacker with reconnaissance data that reduces the effort and risk of follow-up attacks.

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Why this matters — practical impact

1. Reconnaissance and targeted attacks
   Exposed attributes provide an attacker with context about how your SSO is configured and may reveal identifiers, endpoints, or field mappings that can be abused. That makes brute‑forcing, credential stuffing, or social engineering attacks easier and more effective.
2. Credential or token exposure (possible)
   While the report does not state that full tokens or passwords are present, debug/test outputs sometimes include API keys or incomplete tokens which can be abused or used with additional information gathering.
3. Privilege escalation and account mapping
   SSO integrations map external identities to WordPress roles or accounts. Knowledge of how those mappings are structured makes it easier to craft impersonation or attribute-based attacks.
4. Chainable vulnerability risk
   This issue may be combined with other vulnerabilities (e.g., weak endpoints, poorly configured access control elsewhere) to escalate into a more serious compromise.
5. Exposure to automated exploitation
   Because the function can reportedly be called without authentication, mass scanning and automated tooling can quickly identify and fingerprint vulnerable sites at scale.

Given these risks, even a vulnerability flagged as “low” in raw CVSS terms should be addressed quickly — particularly where SSO functionality and user accounts are involved.

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How attackers might abuse this (high level)

We will not provide exploit code or step‑by‑step instructions. The following are conceptual steps an attacker may take to leverage the vulnerability:

1. Discover the vulnerable endpoint or action (e.g., via automated scanners probing plugin files, common WordPress AJAX endpoints like admin-ajax.php, or plugin-specific REST/endpoint URLs).
2. Call the function/action associated with “moym_display_test_attributes” without providing credentials.
3. Parse the returned data for useful information such as attribute names, debug flags, API endpoints, user identifiers, or device identifiers.
4. Use that information for follow‑up activity:
   • Profile SSO mappings and attempt to craft login attempts or tokens.
   • Launch targeted phishing or social engineering to obtain user credentials or tokens.
   • Combine with other vulnerabilities to escalate access.

Because many hosting providers and security teams rely on automated scanners, the discovery stage can be fully automated — meaning a successful scan of vulnerable sites can scale quickly.

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Detection — how you can check if you’re affected

1. Inventory plugins
   – Check all your WordPress sites for the “Login with YourMembership” / YM SSO Login plugin. If it is installed and the version is <= 1.1.7, the site is likely vulnerable.
2. Log inspection
   – Review web server access logs and WordPress logs for suspicious requests to:
   • admin-ajax.php?action=moym_display_test_attributes (or similar action names)
   • plugin file endpoints (any URL path containing /login-with-yourmembership/ or the plugin slug)
   • Any POST or GET requests that return non‑public JSON or data containing the substring “test” or “moym”

   – Look for requests with strange user agents, repeating attempts from the same IP, or requests that return HTTP 200 with unexpected bodies for unauthenticated users.

3. Application scanning
   – Run a trusted WordPress security plugin or external scanner (or have your security provider scan your site) to identify the vulnerable plugin and flag the missing authorization issue.
4. Manual check (defensive, read‑only)
   – If you are a site admin and you know how to inspect plugin source code safely, look for the function/method named moym_display_test_attributes (or similar) and confirm whether it performs capability checks (e.g., current_user_can('manage_options') or checks a nonce) before outputting data. If no such checks exist, the code is vulnerable.

重要： Do not run any intrusive exploitation attempts against other people’s sites. Scanning and testing should be limited to sites you own or have explicit permission to test.

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Immediate mitigations (apply now)

If you cannot immediately remove or update the plugin (and the vendor has not published a patch), apply one or more of the following mitigations:

1. Disable or remove the plugin (recommended if the feature is not essential)
   – If your site does not require the YM SSO Login plugin for normal operation, deactivate and delete it. This immediately removes the attack surface.
2. Restrict access to the plugin endpoints using a WAF or server rules (virtual patching)
   – Block requests that invoke the vulnerable action or function. For example:
   • Block requests to admin-ajax.php when action=moym_display_test_attributes.
   • Block requests to known plugin file paths used by the function.

   – If your WAF supports pattern matching, deny any unauthenticated request that contains the parameter name associated with the test attributes.
   – If you use nginx or Apache, add rules to return 403 for requests containing the relevant query parameter or path. (Examples are below.)

3. Add authentication checks at the server level for the plugin files
   – Use .htaccess, nginx rules, or basic auth to prevent unauthenticated access to plugin PHP files. This is a blunt but effective approach until an official patch is available.
4. Limit access by IP (if possible)
   – If only known IP ranges or internal staff need the test functionality, restrict access to those IPs via firewall or server rules.
5. Remove or sanitize the vulnerable function temporarily
   – If you have development and deployment capability and are comfortable editing plugin code, you can rename or comment out the function that outputs test attributes. Make a back-up before changes. Note: Be cautious and test in staging first; editing plugin code can break functionality.
6. Hide error output and debugging in production
   – Ensure WP_DEBUG and related debug logging are disabled on production. Turn off display_errors and logging of stack traces to public endpoints.
7. Monitor closely
   – Increase log retention and enable alerts for any HTTP 200 responses on plugin endpoints from unauthenticated IPs. Monitor for any signs of account access anomalies.

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Suggested WAF / virtual patching rules (examples)

Below are defensive concepts for WAF rules. These are intentionally generic — adapt to your WAF syntax (mod_security, nginx, Cloud WAF rules, etc). Do not copy exploit payloads.

• Block query parameter action=moym_display_test_attributes in calls to 管理员-ajax.php for unauthenticated sessions.
• Block requests to plugin file path patterns e.g. any request path containing /wp-content/plugins/login-with-yourmembership/ that contain GET/POST parameters like moym 或者 display_test_attributes.
• Rate-limit or challenge all unauthenticated requests that attempt to access plugin endpoints.
• For REST endpoints exposed by the plugin, require an authentication header or deny the endpoint entirely until patched.

Example pseudo-rule (conceptual, not product syntax):

• If request path contains 管理员-ajax.php AND query contains action=moym_display_test_attributes AND user is unauthenticated => return 403 or CAPTCHA challenge.

Another approach is to create a rule that rewrites or intercepts the specific plugin endpoint and returns a generic 403 page unless the request originates from a whitelisted IP.

If you use WP‑Firewall or another WAF, create and deploy a signature that detects the function name or the specific parameter patterns and blocks the request before it reaches PHP.

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Longer-term remediation and best practice

1. Patch management and plugin hygiene
   – Remove unused plugins. Keep required plugins updated and test updates in staging before production.
   – Prefer plugins with active maintenance and responsible disclosure programs (VDP) and clear upgrade timelines.
2. Hardening SSO integrations
   – Treat SSO connectors as critical infrastructure. They map external identities to local roles — mistakes have outsized impact.
   – Use least privilege for SSO mappings. Avoid autopromoting external accounts to admin by default.
3. Principle of least exposure
   – Disable test or debug endpoints in production builds. Many plugins include test functionality that should never be enabled in live sites.
4. Defense in depth
   – Combine layered controls: WAF, host-based restrictions, least-privilege WordPress users, two-factor authentication, and monitoring.
   – Ensure admin area access is restricted by IP or an additional authentication gateway (where possible).
5. Incident response readiness
   – Maintain a documented incident response plan specific to WordPress. Have backups, snapshots, and a trusted cleanup procedure ready.
   – Test backups regularly to ensure they are recoverable.
6. Logging and detection
   – Collect and centralize logs (webserver, WordPress, plugin logs). Create alerts for suspicious patterns like unauthenticated access to plugin endpoints.
   – Use integrity monitoring to detect unexpected file changes.

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If you think you were exploited — what to do now

1. Isolate affected site
   – Put the site into maintenance mode or disconnect from the network where feasible (if you have a multi‑site or shared environment, consult your host).
2. Preserve logs and evidence
   – Export and store current access logs, error logs, plugin logs, and system logs. These will be critical for investigation.
3. Rotate secrets and credentials
   – Change any API keys, SSO client secrets, and administrative passwords that could have been exposed. Do this in a staged manner to avoid breaking legitimate integrations (coordinate with your SSO provider).
4. Perform a full malware and compromise scan
   – Use a trusted scanner and, if available, a security professional to search for web shells, modified files, or backdoors.
5. Rebuild from a known-good backup if necessary
   – If you detect a compromise and cannot confidently remove all malicious artifacts, rebuild the site from a known-clean backup, and then apply hardening and the above mitigations.
6. Post‑incident actions
   – Analyze the root cause, close the gap (remove plugin, apply WAF rule, install patch), and document lessons learned to prevent recurrence.

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Monitoring and detection guidance (practical)

• Create an alert rule for any unauthenticated 200 response that contains the substring “moym” or “test_attributes” in the response body.
• Alert on repeated failed login attempts after anomalous exposure (indicator of reconnaissance leading to brute force).
• If you use centralized SIEM, create a correlation rule: (access to vulnerable endpoint) + (subsequent successful login within 48 hours from same IP) => high priority incident.

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Why virtual patching (WAF / vPatch) matters here

When a plugin vendor has not yet issued a fix, virtual patching is your fastest protective option. A WAF can intercept and block malicious requests that target the vulnerable function without waiting for a code change. Virtual patching reduces risk window and buys time for proper patch testing and deployment.

WP‑Firewall’s virtual patching focuses on minimal, targeted rules that avoid breaking legitimate traffic while preventing unauthenticated access to the vulnerable function. Our approach balances precision (to avoid false positives) with coverage (to stop mass automated scans and malicious requests).

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Communication plan for managed sites and stakeholders

If you manage WordPress sites for clients or for internal teams, treat this advisory as security‑relevant communication:

• Notify site owners and administrators that a vulnerability affects YM SSO Login <=1.1.7 and that an immediate mitigation is recommended.
• Explain the steps you will take: audit plugin presence, enforce WAF rules, monitor logs, and coordinate a plugin update once it becomes available.
• If you manage SSO integrations, coordinate with identity providers to rotate any client secrets if you suspect data leakage.

Clear and prompt communication helps reduce panic and ensures remediation steps are followed correctly.

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Example server-level quick fixes (conceptual)

These examples show defensive ideas. Always test on staging and tailor to your environment:

• Apache (.htaccess) — deny access to a plugin PHP file (example path):
  – If plugin exposes an easily identifiable file, return 403 for direct access to it.
• nginx — return 403 for admin-ajax.php calls containing the vulnerable action:
  – Inspect query string and return 403 when action=moym_display_test_attributes is present.

Remember: be cautious and avoid blocking legitimate admin operations. Narrow rules as much as possible (e.g., only apply to unauthenticated sessions, or only block specific query parameters).

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Recommended checklist for administrators

1. Search all sites for the plugin and identify version numbers.
2. If plugin exists and version <= 1.1.7, immediately do one or more of:
   • Deactivate and remove the plugin (if feasible), OR
   • Apply WAF rule to block the vulnerable action/endpoint, OR
   • Restrict plugin file access via server rules / IP restrictions.
3. Audit logs for access to plugin endpoints over the past 30 days.
4. Rotate SSO client secrets if you find suspicious activity or if the plugin is integral to SSO authentication.
5. Prepare a remediation plan to replace the plugin with an alternative integration or to coordinate patching with vendor when available.
6. Enable monitoring for related indicators (suspicious admin logins, new administrator accounts, unexpected file changes).
7. Document actions and communicate to stakeholders.

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How WP‑Firewall helps (our approach)

At WP‑Firewall we focus on rapid detection and precise virtual patching for vulnerabilities like this. Key activities we recommend and provide:

• Precise WAF signatures to block unauthenticated calls to the vulnerable function without disrupting normal traffic.
• Automated site inventory to identify all installations using vulnerable plugin versions across your portfolio.
• Monitoring and alerting tuned to detect reconnaissance patterns and follow‑on attack behavior.
• Guidance and safe procedures for emergency code changes if plugin removal is not immediately possible.
• Post‑incident cleanup procedures and support to validate that a site is clean.

If you operate multiple WordPress sites or manage client environments, these capabilities significantly reduce your exposure window and provide operational confidence until an official plugin fix is available.

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Final notes and responsible disclosure

• Treat this advisory as time‑sensitive. The vulnerability allows unauthenticated access to internal attributes and should be mitigated promptly.
• If you are a plugin author or site owner with additional, verifiable technical details about the moym_display_test_attributes behavior, please coordinate responsible disclosure with the plugin vendor and your security provider.
• Avoid public disclosure of exploit details; share technical proof responsibly only with trusted parties or under responsible disclosure programs.

If you want help implementing virtual patches, crafting precise WAF rules, or auditing your site for this issue, WP‑Firewall’s engineering team can assist with triage, rule deployment, and monitoring to keep your WordPress installations safe until a permanent patch is available.

Stay safe, and treat SSO integrations as high‑priority security assets.

— WP‑Firewall Security Team