插件名称	Accessibility Checker by Equalize Digital
漏洞类型	不安全的直接对象引用（IDOR）
CVE 编号	CVE-2025-57886
急	低的
CVE 发布日期	2025-08-22
源网址	CVE-2025-57886

Accessibility Checker (≤ 1.30.0) — IDOR Vulnerability (CVE-2025-57886): What WordPress Site Owners Need to Know

已发布: 2025-08-22
作者： WP‑Firewall Security Team

概括

A contributor‑level Insecure Direct Object Reference (IDOR) was reported in the Accessibility Checker plugin by Equalize Digital affecting versions ≤ 1.30.0 and fixed in 1.30.1 (CVE-2025-57886). In this post we explain what changed, how this class of vulnerability works, how to assess exposure, and practical step‑by‑step mitigation and hardening actions you can apply immediately — including how a modern WAF and virtual patching can protect your site while you patch.

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TL;DR

• A contributor‑level IDOR in Accessibility Checker ≤ 1.30.0 lets an authenticated user (contributor role) access or manipulate objects they shouldn’t be allowed to.
• CVE: CVE-2025-57886. Fixed in Accessibility Checker 1.30.1.
• Severity assigned: CVSS 5.4 (Medium / Low patch priority) — impacts depend on your site setup and how the plugin is used.
• Immediate actions: 1) Update the plugin to 1.30.1+, 2) restrict contributor access to the plugin UI until patched, 3) enable WAF / virtual patching to block unauthorized object access patterns.
• If you run multiple sites, prioritize updating and consider virtual patching to protect sites that cannot be immediately updated.

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Background: What is an IDOR and why it matters

Insecure Direct Object References (IDOR) occur when an application exposes an internal object identifier (for example, a database row ID, file path, or token) in a URL or parameter and fails to enforce proper authorization checks server‑side. Attackers who can change that identifier can gain access to data or actions belonging to other users.

Typical consequences of IDOR include:

• Reading or modifying other users’ records (files, reports, settings).
• Performing actions as someone else (posting, deleting, changing configuration) if the endpoint lacks authorization.
• Exfiltrating sensitive data (email addresses, uploaded files).

Unlike remote code execution or SQL injection, IDORs require authentication in many cases — but that doesn’t make them harmless. If an attacker can register or obtain a low‑privileged account (contributor/author) they may escalate the impact by accessing resources intended for admins.

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The Accessibility Checker issue in plain language

• A security researcher reported an IDOR in the Accessibility Checker plugin that allowed a user with the Contributor role to access objects (reports, scans, or admin resources) tied to other users or global data.
• The plugin versions ≤ 1.30.0 did not correctly verify that the authenticated user was authorized for the requested object(s).
• The plugin author released 1.30.1 which contains the fix — server‑side authorization checks to ensure requested objects belong to or are permitted for the requester.

Important details to keep in mind:

• The vulnerability requires an authenticated account (Contributor).
• The CVSS is moderate because exploitation requires authentication, but the real impact depends on what the plugin stores and exposes (e.g., attachments, URLs, or scan data).
• The vulnerability is fixed in 1.30.1 — updating removes the risk.

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How to quickly check if you’re affected

1. In WordPress admin, go to Plugins → Installed Plugins and find “Accessibility Checker.”
2. If the installed version is ≤ 1.30.0 you are affected; update to 1.30.1 or later.
3. If you cannot update immediately:
   • Temporarily deactivate the plugin.
   • Or restrict who can access the plugin (see immediate mitigations below).

If you manage many sites, script a version check and prioritize sites where contributor accounts exist for non‑trusted users or where the plugin is mission‑critical.

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Exploitation scenarios (what an attacker could do)

NOTE: We will not provide exploit code or step‑by‑step instructions that would enable abuse. The following high‑level scenarios describe real risks so you can triage and protect.

• A malicious contributor enumerates object identifiers exposed by the plugin (IDs in URLs, form fields, AJAX parameters) and iterates them to access other users’ scan results or uploaded attachments.
• A contributor could export or view data they should not (private scan data, site diagnostics, URLs containing sensitive tokens).
• If the plugin stores or references uploaded files (for example, attachments for accessibility reports), an attacker may access files uploaded by other users.
• If the plugin exposes configuration or links to external systems, an attacker could gather information useful for follow‑up attacks.

Impact varies — some sites may only expose non‑sensitive accessibility scan metadata, others may expose PII or internal URLs. Inspect how your site uses the plugin.

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Detection: How to detect attempted exploitation

Monitor server and application logs for suspicious patterns that are commonly associated with IDOR attempts:

• Repeated requests to the same endpoint with sequential changes to integer identifiers (e.g., id=1, id=2, id=3).
• Contributor‑role accounts issuing requests to admin‑only endpoints or resources they normally cannot view.
• Unusually high rate of access to resource endpoints returning different owner IDs.
• Requests to plugin AJAX endpoints that include object IDs or paths from differing accounts.

Example indicators you can search for in access logs (replace plugin endpoints with the actual endpoint path on your site):

• Query string patterns: /wp-admin/admin-ajax.php?action=ac_get_report&report_id=123
• Sequential numeric requests from one IP or user account
• 200 responses to resource accesses by contributor accounts which normally should be forbidden

If you find suspicious activity, consider rotating credentials for affected users and follow the incident response steps outlined below.

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Immediate mitigations (what to do right now)

1. Update the plugin to 1.30.1 or later (preferred, fast, and complete fix).
2. If you cannot update immediately:
   • Remove or deactivate the plugin on high‑risk sites.
   • Limit Contributor role capabilities temporarily (see capability hardening below).
   • Disable plugin endpoints by blocking access with your WAF until you can update (pattern‑based rule for AJAX endpoints).
3. Audit user accounts:
   • Remove or convert unneeded Contributor accounts.
   • Check for suspicious accounts created recently.
4. Harden uploads and file access:
   • Ensure uploaded files are stored in locations that enforce permission checks.
   • Prevent direct listing or public access to internal upload paths where possible (use signed URLs or rewrite rules).
5. Monitor logs and set alerts for enumeration patterns described in the Detection section.
6. Rotate sensitive secrets if you suspect exposure (API tokens, keys, or integration credentials).

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Capability hardening: practical WordPress steps

If you need a quick server‑side stopgap while applying the plugin update, you can modify contributor capabilities to temporarily narrow their allowed actions. The safest approach is time‑limited and reversible.

Example (safe) approach using a small mu‑plugin:

<?php
/*
Plugin Name: Temp Contributor Capability Hardening
Description: Temporarily remove risky capabilities from contributor role.
Version: 0.1
*/

// RUN ONLY TEMPORARILY: remove sensitive capabilities from contributors.
add_action('init', function () {
    $role = get_role('contributor');
    if ( ! $role ) {
        return;
    }
    // Example: remove edit_published_posts if you want to prevent some actions
    // $role->remove_cap('edit_published_posts');

    // A conservative approach is to prevent access to the plugin admin page,
    // using a capability that only editors/admins have:
    add_filter('map_meta_cap', function($caps, $cap, $user_id, $args) {
        if ( in_array($cap, ['access_ac_plugin_admin']) ) {
            $caps = ['manage_options']; // require admin
        }
        return $caps;
    }, 10, 4);
});

Notes:

• Do not rely on this as a long‑term fix. Update the plugin as soon as possible.
• Test changes on a staging site first. Capability adjustments can affect editorial workflows.

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WAF and Virtual Patching: how they help, and what to configure

A modern WordPress WAF can protect you while you apply the official fix by blocking the exploitation patterns that the IDOR relies on. Virtual patching (vPatching) means deploying a protective rule that intercepts malicious requests and prevents them from reaching the vulnerable code.

Key WAF rules to deploy for IDOR protection:

• Parameter tampering detection: block requests where object identifiers are changed in ways uncommon to legitimate usage (rapid enumeration of sequential IDs).
• Role‑based endpoint protection: block requests to plugin admin or AJAX endpoints made by Contributor role sessions or by requests missing valid admin cookies/nonces.
• Request rate‑limiting: throttle an authenticated account that is making many sequential object access requests.
• Block common attack vectors: deny access to suspicious referers, known bad IPs, or requests with known automation fingerprints.

What we recommend:

• Configure a rule to inspect requests to the plugin’s endpoints and allow only authorized capability flows (e.g., only administrators or the object owner).
• If you use virtual patching, create a temporary rule that returns a safe response (403) for unauthorized object access where the current user does not match the object owner.

重要： Virtual patches are a protective measure until you install the official update. They should not replace the upstream fix.

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How WP‑Firewall can help (features to use)

As a security provider focused on WordPress, the following measures are effective:

• Managed WAF rules that detect IDOR patterns and block suspicious parameter tampering for known vulnerable endpoints.
• Virtual patching to immediately mitigate the vulnerability across many sites while plugin updates are staged.
• Malware scanning to ensure no follow‑on file drops or persistence mechanisms were installed by a post‑exploit attacker.
• Monitoring and alerts for indicators of enumeration and unauthorized access attempts.
• Role and capability auditing tools to help control contributor accounts across environments.

If you run multiple sites or manage client environments, apply virtual patching first and then schedule plugin updates to avoid unexpected interruptions.

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Incident response: If you suspect you were exploited

If you find signs of abuse related to this vulnerability, follow a standard incident response workflow:

1. Contain:
   • Immediately update the plugin (1.30.1+) on affected sites or disable the plugin temporarily.
   • If update is not possible, enforce WAF rules to block access to the vulnerable endpoints and suspend suspicious contributor accounts.
2. Preserve evidence:
   • Save relevant logs (webserver, PHP, plugin logs) and copies of affected files for forensics.
   • Note timestamps, IP addresses, and user account identifiers.
3. Investigate:
   • Look for unexpected file uploads, new admin users, or malicious scheduled jobs.
   • Check database tables for unauthorized changes associated with plugin object IDs.
4. Eradicate:
   • Remove any webshells, backdoors, or malicious cron jobs.
   • Rotate API keys and credentials that may have been exposed.
5. Recover:
   • Restore cleaned backups if necessary and update all plugins and WP core.
   • Reapply stricter user controls and credentials.
6. Review and Learn:
   • Conduct a root‑cause analysis to understand how access occurred and what controls failed.
   • Update incident playbooks and apply lessons learnt across all your sites.

If you are uncertain about the scope of compromise, engage a professional incident responder.

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Longer‑term hardening and best practices

Beyond the immediate fix, adopt these durable controls:

• Principle of least privilege: limit contributor permissions only to what’s needed. Remove the ability to upload files unless strictly required.
• Plugin governance: only install plugins from trusted sources and keep an inventory of plugins and versions across sites.
• Regular scanning and SCA: use software composition analysis or plugin monitoring tools to detect vulnerable versions proactively.
• Staging and testing: deploy plugin updates first in a staging environment; test quickly and then roll out.
• Two‑factor authentication: require 2FA for all accounts with contributor and above roles where possible.
• Audit trails & alerting: centralize logs and set alerts for unusual user behavior (high request rates, sequential ID access).
• Backup and restore plan: ensure backups are up‑to‑date and regularly tested.

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Example developer fix pattern

At a conceptual level, the fix for an IDOR is always to verify ownership or permissions server‑side before returning an object. A typical check in WordPress plugin code:

<?php
$report_id = intval( $_GET['report_id'] ?? 0 );
$report = get_report_by_id( $report_id );

if ( ! $report ) {
    wp_send_json_error( 'Report not found', 404 );
}

// Ensure current user is authorized to access this report
$current_user_id = get_current_user_id();
if ( $report->owner_id !== $current_user_id && ! current_user_can('manage_options') ) {
    wp_send_json_error( 'Forbidden', 403 );
}

// Continue returning the requested data
wp_send_json_success( $report->to_array() );

Key points:

• Never rely on client‑side controls (JS checks, hidden fields) for authorization.
• Always validate and sanitize incoming IDs.
• Use capability checks appropriate to the object sensitivity; owner checks are common.

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Detection rules and WAF signatures (high level)

If you manage a WAF, consider rules that detect and intercept the following behaviors:

• Authenticated requests to plugin endpoints where a parameter like report_id, scan_id, file_id appears, and the requesting user is not the owner.
• Requests with sequential integer IDs from the same IP or account within a short window (enumeration).
• AJAX calls to admin-ajax.php carrying plugin-specific action names with mismatched cookie/capability flows.
• Requests where Contributor role cookies are used to fetch admin-only resources.

Implementations vary by WAF technology. If your WAF supports user role detection (via session cookies + server validation), you can create role‑based allow/deny rules. Otherwise use behavioral and parameter rules.

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Risk assessment for different site types

• Small brochure sites with only editors and admins: Low risk unless contributors are used.
• Multi‑author blogs and membership sites: Higher risk because contributor or member roles may exist and be usable to exploit IDOR.
• Sites with plugin integrations storing sensitive data: Elevated risk if plugin objects include PII or private URLs.
• Agency or client sites with many contributors: Prioritize patching across the fleet.

Always evaluate your site’s specific exposure and available contributor accounts.

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经常问的问题

问： I don’t use the Accessibility Checker plugin — am I affected?
A： No. Only sites running Accessibility Checker versions ≤ 1.30.0 are impacted.

问： I updated to 1.30.1 but still see suspicious accesses in logs — what now?
A： Update is essential. After updating, continue monitoring logs and scan for indicators of compromise. If you suspect a successful exploit prior to patching, follow the incident response steps.

问： Is virtual patching safe to rely on?
A： Virtual patching is an excellent interim protective measure but not a replacement for the upstream fix. Apply virtual patching to buy time and reduce exposure while you update.

问： Should I disable contributor accounts instead?
A： For critical short‑term risk reduction you can downgrade or suspend untrusted contributor accounts. This may disrupt editorial workflows, so balance risk and operations.

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Checklist: What to do now (step‑by‑step)

1. Confirm plugin version. If ≤ 1.30.0, update to 1.30.1+ immediately.
2. If you cannot update right away:
   • Deactivate the plugin OR
   • Deploy WAF rules / virtual patch to block targeted endpoints OR
   • Restrict contributor accounts temporarily.
3. Audit contributor roles and remove unneeded accounts.
4. Monitor logs for enumeration patterns and unusual file downloads.
5. Run a malware and file integrity scan after patching to check for signs of compromise.
6. Ensure backups are verified and stored offsite.
7. Schedule plugin updates and keep an inventory of all installed plugins.

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Why this helps: virtual patching and WAF rules can be applied instantly across your site(s), providing immediate protection from attempts to exploit IDOR patterns while you manage updates and user access.

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Closing thoughts from the WP‑Firewall security team

IDOR vulnerabilities are a reminder that secure software design requires server‑side authorization checks on every object access. Attackers don’t always need to bypass authentication — they exploit gaps in authorization logic. For WordPress administrators, the practical steps are straightforward: inventory, patch, harden, and monitor.

• Update Accessibility Checker to 1.30.1 or later now.
• Review contributor accounts and tighten permissions where practical.
• If you manage multiple sites, use a WAF and virtual patching to protect quickly and consistently.
• Invest a small amount of time to harden upload paths and add monitoring to get an outsized reduction in risk.

If you’d like help triaging vulnerable sites, deploying virtual patches, or reviewing logs for possible exploitation indicators, our team is available to assist.

Stay safe — and keep your WordPress sites updated and monitored.

— WP‑Firewall Security Team