| 插件名稱 | Everest Backup |
|---|---|
| Type of Vulnerability | Authorization bypass |
| CVE Number | CVE-2025-11380 |
| Urgency | 中等的 |
| CVE Publish Date | 2025-10-10 |
| Source URL | CVE-2025-11380 |
Everest Backup <= 2.3.5 – Missing Authorization Enables Unauthenticated Backup Data Exposure (CVE-2025-11380) – Immediate Actions for Site Owners
作者： Managed-WP Security Team
Date: 2025-10-11
標籤： WordPress, Security, Vulnerability, Everest Backup, CVE-2025-11380, Incident Response
Overview: A critical broken access control flaw (CVE-2025-11380) discovered in Everest Backup plugin versions up to 2.3.5 allows unauthenticated users to access sensitive backup information. This vulnerability was addressed in version 2.3.6. This article details the technical nature of the risk, potential exploitation methods, detection and investigation guidance, immediate mitigation strategies—including virtual patching via Managed-WP firewall—and recommended developer fixes to safeguard WordPress sites.
Executive Summary
On October 10, 2025, a broken access control vulnerability affecting Everest Backup plugin versions ≤ 2.3.5 was publicly disclosed and assigned CVE-2025-11380. This flaw arises from insufficient authorization checks on certain plugin endpoints, enabling unauthenticated visitors to access backup metadata and, under some configurations, potentially download backup files themselves.
Risk rating: Medium (CVSS 5.9). Impact: Exposure of backup file names, URLs, and possibly direct access to backup archives containing sensitive site data. Exploitation greatly assists attackers in reconnaissance and facilitates subsequent attacks such as credential harvesting or privilege escalation. Everest Backup version 2.3.6 includes a security update enforcing proper access controls. Site owners must prioritize immediate updates or, if not possible, deploy recommended mitigations including Managed-WP’s virtual patching capabilities.
Why This Vulnerability Demands Your Attention
WordPress backups contain comprehensive snapshots of your website, often including databases, configuration files, and user data. Any exposure of backup listings or direct download links to unauthenticated users presents a significant threat, as attackers can:
- Enumerate available backups and select potentially valuable data.
- Download full database exports, revealing sensitive user credentials and information.
- Disclose site architecture, plugin versions, and administrative usernames.
- Leverage stolen data to launch targeted phishing campaigns or further infiltrate the site.
Backup endpoints must enforce strict authorization. Failure to do so should be treated as a high-severity incident.
Technical Summary of the Vulnerability
- Affected software: Everest Backup WordPress plugin
- Vulnerable versions: ≤ 2.3.5
- Resolved in: 2.3.6
- CVE identifier: CVE-2025-11380
- Vulnerability type: Broken Access Control (OWASP A5)
- Exploit access: Public (unauthenticated)
Details: Certain endpoints exposed backup information without validating user authentication or required permissions. As a result, attackers could retrieve backup metadata and, in some setups, directly download backup files, bypassing proper access control.
Exploitation Scenarios
- Backup Enumeration: Attackers request the backup listing endpoint, obtaining details such as file names, sizes, and timestamps, enabling selection of specific backups to target.
- Direct Backup Download: Unauthenticated access to download URLs allows attackers to retrieve full backup archives containing critical data including wp-config.php and database dumps.
- 自動掃描： Bots systematically scan for vulnerable Everest Backup installations and access exposed endpoints at scale.
- Credential Harvesting and Lateral Movement: After backup retrieval, attackers extract credentials, keys, or secrets to escalate privileges or pivot within the site or network.
Because no authentication is required to trigger the vulnerability, exploitation at scale is a realistic, ongoing threat until sites are patched or mitigated.
Immediate Action Plan for Site Owners
- Update Everest Backup to version 2.3.6 immediately. This is the most effective protection.
- If instant updating is not feasible, deactivate the plugin temporarily. This removes the vulnerable endpoints from exposure.
- Enable virtual patching via Managed-WP firewall. Activate the provided Managed-WP firewall rules targeting Everest Backup to block unauthorized access.
- Implement server-level restrictions: Use web server configuration to restrict access to plugin directories and related REST endpoints.
- Analyze logs for suspicious activity. Search server and firewall logs for requests related to Everest Backup paths or backup downloads.
- Rotate sensitive credentials and secrets. If backups were accessed during the vulnerable window, change database passwords, API keys, and administrative passwords immediately.
- Preserve forensic evidence. Keep copies of logs, backups, and other indicators during investigation.
Detecting Potential Probing or Exploitation
To determine if your site was targeted or compromised, examine your server and Managed-WP firewall logs for requests matching these patterns:
- Requests to
/wp-content/plugins/everest-backup/or subdirectories. - REST API calls under
/wp-json/everest-backup/or any route containing “everest”. - Admin AJAX actions with query parameters or action names associated with backups.
- Requests resulting in large file responses or direct backup downloads.
Example command snippets for Linux servers:
# Apache or nginx logs:
zgrep -i "everest-backup" /var/log/apache2/access.log* | less
zgrep -i "wp-json" /var/log/nginx/access.log* | grep -i everest
zgrep "admin-ajax.php" /var/log/nginx/access.log* | grep -i "backup\|everest"
Indicators include unusual user agent strings, requests originating from suspicious IPs, or large file downloads.
Confirmed backup downloads should trigger comprehensive incident response immediately.
Indicators of Compromise (IOCs)
- Unrecognized IP addresses accessing the plugin or REST endpoints.
- HTTP 200 responses delivering archive files (e.g., content-types: application/zip, application/octet-stream).
- Unexpected outbound traffic spikes coinciding with endpoint access.
- Post-exploit activities such as new admin users or unauthorized site modifications.
Detection of any IOCs warrants immediate credential rotation and a thorough malware and integrity scan.
Mitigation Strategies (Before Applying Vendor Patch)
These measures reduce exposure risk temporarily and can be reversed once the official update is deployed. Always test changes in a staging environment first.
1. Plugin Deactivation
Disable Everest Backup from WordPress Admin at Plugins → Installed Plugins. If the backup function is critical, consider alternate mitigations below.
2. IP-Based Access Restriction (Apache .htaccess)
# In /wp-content/plugins/everest-backup/.htaccess
<IfModule mod_authz_core.c>
Require ip 203.0.113.0 198.51.100.14
Require all denied
</IfModule>
<IfModule !mod_authz_core.c>
Order deny,allow
Deny from all
Allow from 203.0.113.0
Allow from 198.51.100.14
</IfModule>
3. Nginx Location Block
# Insert into nginx server block
location ~* /wp-content/plugins/everest-backup/ {
deny all;
# alternatively:
# allow 203.0.113.0;
# deny all;
}
4. Managed-WP Firewall or ModSecurity Rules
Block access to plugin directories and REST endpoints with rules such as the examples below:
# Block plugin folder access
SecRule REQUEST_URI "@contains /wp-content/plugins/everest-backup/" \
"id:100901,phase:1,deny,log,msg:'Blocked Everest Backup plugin path access'"
# Block REST API access
SecRule REQUEST_URI "@rx /wp-json/.*everest.*" \
"id:100902,phase:1,deny,log,msg:'Blocked Everest Backup REST API access'"
5. Temporary Access Control via WordPress Filter
Insert the following mu-plugin to restrict public access to plugin endpoints:
<?php
// File: wp-content/mu-plugins/everest-backup-block.php
add_action('admin_init', function() {
if ( ! is_user_logged_in() && isset($_SERVER['REQUEST_URI']) ) {
$uri = wp_unslash($_SERVER['REQUEST_URI']);
if ( strpos( $uri, '/wp-content/plugins/everest-backup/' ) !== false
|| strpos( $uri, '/wp-json/everest-backup' ) !== false ) {
status_header(403);
exit('Access forbidden.');
}
}
});
Note: This is a stop-gap measure and should be tested for compatibility.
Managed-WP Virtual Patching: Recommended Strategy
Sites protected with Managed-WP benefit from immediate rule activation protecting Everest Backup endpoints:
- Block unauthenticated access to the plugin directory (
/wp-content/plugins/everest-backup/*). - Restrict access to REST API routes under the Everest Backup namespace.
- Prevent downloads of sensitive backup file types unless authorized.
- Rate-limit backup listing or download requests to prevent abuse.
- Alert on suspicious large file responses or unusual activity in logs.
- Implement geo/IP-based restrictions if traffic is not global.
- Enforce session cookie and nonce validation on all sensitive endpoint requests.
Virtual patching enables rapid protection without modifying plugin code, providing time to perform comprehensive testing and update routines.
Verifying Successful Remediation
After patching or applying mitigations:
- Attempt anonymous backup listing/retrieval—requests should be denied or show no sensitive information.
- Check firewall logs for blocked attempts matching vulnerable endpoints.
- Run internal scans against plugin endpoints to confirm no unauthorized data exposure.
- Ensure no caching layers are serving stale vulnerable content.
Long-Term Security Recommendations
- Always keep WordPress core, themes, and plugins current.
- Maintain an up-to-date plugin inventory to identify vulnerabilities early.
- Remove unused or inactive plugins.
- Apply least privilege principles on plugin capabilities.
- Store backups securely, off server where possible, and encrypt backup files.
- Implement strict server-level authentication and access control on backup storage.
- Use WordPress nonces and capability checks on all endpoints handling sensitive operations.
- Maintain thorough logging and actively monitor for anomalies.
- Conduct periodic security audits and code reviews on critical plugins.
Guidance for Plugin Developers
- Implement authorization checks on all endpoints, preferring capabilities like
manage_options. - Enforce server-side authentication validation—do not rely on obscurity.
- Use and verify WordPress nonces for admin-ajax and REST API requests.
- Never serve backup files publicly; if necessary, enforce server-level authentication.
- Sanitize all inputs and restrict data output to authorized users only.
- Require HTTPS and use signed, expiring links for temporary download access.
- Develop automated tests verifying unauthorized access is prevented.
- Maintain a responsible vulnerability disclosure policy (VDP).
Incident Response Checklist for Confirmed Exposure
- Identify and log the timeframe plus IP addresses that requested backup resources.
- Preserve web, application, and firewall logs for forensic analysis.
- Immediately rotate sensitive credentials—database passwords, API tokens, admin credentials.
- Generate new salts and tokens where applicable.
- Force password resets for all privileged users.
- Remove any compromised files and rebuild from trusted sources.
- Scan the site for malware, web shells, or unauthorized admin accounts.
- Notify affected stakeholders and comply with breach reporting laws.
- Post-incident review to prevent recurrence and bolster defenses.
Sample Detection Queries and Log Indicators
- Search Apache/nginx access logs for plugin requests returning 200 status:
GET /wp-content/plugins/everest-backup/with status 200
- Look for large Content-Length values on GET requests (e.g., > 100KB).
- Managed-WP firewall logs indicating rule triggers such as:
- Rule ID 100901: Blocked Everest Backup plugin path access
Use appropriate tools on your server or hosting control panel to perform these searches regularly during incident response.
The Critical Role of Virtual Patching
With public disclosure of backup plugin vulnerabilities, attackers waste no time exploiting exposed endpoints. Virtual patching via Managed-WP firewall provides an essential protective barrier by intercepting and blocking malicious HTTP requests targeting vulnerable paths.
Advantages include:
- Immediate reduction of attack surface without modifying plugin code.
- Centralized, easy rule deployment and rollback.
- Enhanced monitoring and alerting on exploitation attempts.
Managed-WP’s virtual patching rules are specifically crafted for WordPress environments to ensure blocked attack vectors while maintaining legitimate functionality.
Suggested WAF Rules: Human-Readable Examples
- Block all GET requests to
/wp-content/plugins/everest-backup/*from unauthenticated IPs. - Deny REST API calls matching
/wp-json/*everest*/*unless authenticated via valid session. - Flag and block query parameters like
download=或者file=targeting backup plugin folders. - Rate-limit backup listing endpoints to no more than 10 requests per minute per IP.
Always test rules in non-blocking mode initially to avoid unintended disruption.
常問問題
Q: After updating to 2.3.6, is further action required?
A: Update promptly first. Then validate endpoint behavior and rotate credentials if backups were exposed beforehand.
Q: Does deleting old backups remove the risk?
A: No. While deleting old backups reduces data at risk, patching the vulnerability and securing backups remain essential.
Q: Does deactivating Everest Backup delete backups?
A: Typically, no. Backup files often remain on disk. Review plugin documentation and manually remove any sensitive files if necessary.
Best Practices for Responsible Disclosure
- Report vulnerabilities privately to the plugin vendor or via their published VDP.
- Provide detailed reproduction steps, affected version info, and remediation suggestions.
- Allow reasonable time for response before public disclosure.
- If active exploitation occurs without vendor response, notify hosting providers and consider coordinated disclosure.
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Final Thoughts from the Managed-WP Security Experts
Backup plugins hold a critical security posture because they manage comprehensive snapshots of site data. Broken access control on such components is a top-tier risk. It demands immediate detection, blocking, patching, verification, and long-term hardening.
If you require expert assistance in investigation, hardening, or deploying virtual patches, Managed-WP’s security team is ready to support you. Protecting your site backups and the sensitive information they store is fundamental to your WordPress security strategy.
Stay vigilant, update promptly, and monitor diligently.
— Managed-WP Security Team
