Tên plugin	Assistant for NextGEN Gallery
Type of Vulnerability	Unauthenticated Directory Deletion
CVE Number	CVE-2025-7641
Tính cấp bách	Cao
CVE Publish Date	2025-08-15
Source URL	CVE-2025-7641

Urgent: CVE-2025-7641 — Unauthenticated Path Traversal & Arbitrary Directory Deletion in Assistant for NextGEN Gallery (<= 1.0.9)

A practical, expert guide from WP‑Firewall on the unauthenticated path traversal and arbitrary directory deletion vulnerability in the Assistant for NextGEN Gallery plugin (CVE-2025-7641). What it means for your site, how attackers can abuse it, immediate mitigations, and long-term hardening and monitoring advice.

Ngày: 2025-08-16
Tác giả: WP‑Firewall Security Team
Thể loại: WordPress Security, Vulnerability Advisory, WAF, Incident Response

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Summary: A high‑severity path traversal vulnerability (CVE-2025-7641; CVSS 7.5) affecting Assistant for NextGEN Gallery plugin versions <= 1.0.9 allows unauthenticated attackers to delete arbitrary directories. There is no official patch available at publication. If your site uses this plugin, act immediately to protect data and restore integrity.

Mục lục

• Executive summary
• What this vulnerability is (high level)
• Technical background and why this is dangerous
• Attack scenarios and likely impact
• Why exploitation is realistic and urgent
• Safe detection: how to check if you’re affected
• Immediate mitigations (step‑by‑step)
• Long term remediation and secure configuration
• How a Web Application Firewall (WAF) like WP‑Firewall protects you
• Suggested virtual patch / WAF rule patterns (conceptual)
• Incident response playbook for compromised sites
• For plugin authors: secure coding notes to prevent path traversal and file deletion bugs
• Closing recommendations
• Get protected with a free WP‑Firewall plan

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Executive summary

On 15 August 2025 a publicly disclosed vulnerability (CVE-2025-7641) affecting the Assistant for NextGEN Gallery WordPress plugin (versions <= 1.0.9) was published. The issue is a path traversal (directory traversal) leading to unauthenticated arbitrary directory deletion. Because it requires no authentication, an attacker can target the site remotely and remove directories (for example galleries, uploads, or other important folders), causing data loss and potential site takeover if critical assets are deleted.

This advisory explains what the vulnerability allows attackers to do, how you can check for signs of exploitation, immediate mitigations you should apply (including defensive steps if no official patch exists), and how WP‑Firewall provides protection using virtual patching and layered defenses.

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What this vulnerability is (plain language)

• Kiểu: Path Traversal (directory traversal) that leads to arbitrary directory deletion.
• Privilege: Unauthenticated — anyone on the Internet can invoke the vulnerable endpoint.
• Sự va chạm: Directory deletion inside the webroot or plugin-managed storage — potential loss of images, galleries, plugin configuration, or even site files.
• CVE: CVE-2025-7641
• Mức độ nghiêm trọng: High (CVSS 7.5)
• Các phiên bản bị ảnh hưởng: Assistant for NextGEN Gallery <= 1.0.9
• Vendor patch availability: None at time of disclosure

Path traversal allows an attacker to supply file path fragments like ../ (or encoded variants) to break out of an intended directory. When the application then performs file operations (delete/move/rmdir) without sanitizing inputs, the attacker can operate on arbitrary paths that the web server process has permission to modify.

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Technical background — why directory deletion via path traversal is especially severe

Path traversal vulnerabilities commonly expose file read operations (disclose configuration files, secrets). This case is worse: it enables deletion. Deletions are destructive and can make recovery harder, particularly if automated backups are infrequent or if attackers combine deletion with further destructive or ransomware activity.

Key technical reasons this is severe:

• Unauthenticated: No credentials required. Attackers can scan sites and trigger the delete action en masse.
• Arbitrary directory deletion: Attackers can target wp-content/uploads, plugin-specific folders, or other writable directories. If an attacker deletes backups, uploads, or media libraries, the site may be irreversibly damaged without offsite backups.
• Webserver permissions: The webserver user (e.g., www-data) typically has write access to plugin and upload folders. Deletion operations executed under the webserver user will succeed if permissions allow.
• Automation potential: Attackers build bots that discover vulnerable sites and execute destructive payloads simultaneously across thousands of targets.

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Attack scenarios and likely impact

Below are plausible exploitation scenarios and consequences:

1. Mass removal of media and galleries
   • Sự va chạm: All images in NextGEN galleries removed; broken pages, missing visual content, bad UX.
   • Business consequence: E-commerce product images removed, blog images gone causing brand and revenue damage.
2. Targeting configuration or plugin directories
   • Sự va chạm: Plugin state wiped, site or plugin functionality breaks.
   • Business consequence: Admin interface errors, plugin reinstall required; time and resource costs.
3. Deleting backups or backup directories
   • Sự va chạm: Prevents recovery from the very vulnerability that caused the damage.
   • Business consequence: Extends downtime and increases recovery cost.
4. Chaining with other vulnerabilities
   • Sự va chạm: Deletion as cover for other attacks (replacing files, planting backdoors).
   • Business consequence: Persistent compromise, data exfiltration, and possible account takeover.
5. Induced Denial of Service
   • Sự va chạm: Site fails due to missing assets or critical folders removed.
   • Business consequence: Immediate outage, reputation and SEO damage.

Because the vulnerability is unauthenticated and there’s no official patch at publication, attackers will likely escalate scanning and exploitation attempts quickly.

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Why exploitation is realistic and urgent

• Attackers constantly scan for known vulnerabilities. A public CVE combined with proof-of-concept descriptions increases exploitation likelihood.
• Automation: Scripts can crawl the web, detect the vulnerable plugin signature, and attempt the delete endpoint with path traversal payloads.
• Low attacker effort: No authentication, little to no complexity.
• High payoff: Deleting media or backups is cheap for attackers but expensive for site owners.

If you host multiple WordPress sites or manage client sites, prioritize checking each site immediately.

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Safe detection — how to check if you’ve been targeted (what to look for)

Do not attempt to replicate the vulnerability in a production environment. Instead, collect forensic evidence and look for indicators of compromise (IoCs):

1. Webserver and PHP logs
   • Search for unusual requests to plugin endpoints matching the Assistant for NextGEN Gallery plugin.
   • Example grep patterns (tailor to your environment):

   # Search for suspicious query strings containing ../ or encoded ../
   grep -E "(%2e%2e|%2f%2e|%2e%2f|\.\./)" /var/log/apache2/access.log
   grep -E "assistant-for-nextgen|nextgen-assistant|ngg-assistant" /var/log/apache2/access.log
   

   • Look for HTTP POST/GET to plugin endpoints followed by 200/204/500 responses near file deletion timestamps.
2. File system checks
   • Missing directories under wp-content/uploads or plugin-specific directories.
   • Compare current filesystem to a backup or staging copy.
   • Check for recently deleted files (if you have file system snapshots) and timestamps of rmdir/unlink operations.
3. WordPress audit logs
   • If you use an activity/audit plugin, search for deletions and file-operation-related events associated with the plugin.
   • Note: Because the exploit is unauthenticated, WordPress user activity logs may not show exploit actions.
4. Backup integrity
   • Confirm that offsite backups are intact and not deleted by attacker activity.
   • If backups are compromised, expand investigation scope.
5. Unexpected plugin behavior
   • Plugin errors, warnings in PHP error logs indicating failed file operations.
6. Web application firewall logs (if present)
   • WAF should show blocked requests with traversal patterns if protections were active.

If you find evidence of deletion, do not rebuild in place immediately — collect logs and snapshot the current state for incident investigation.

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Immediate mitigations (step‑by‑step)

When an official patch is not available, use a layered defense approach: block live exploitation, isolate the vulnerable functionality, and prepare recovery.

1. Short-term emergency steps (minutes)
   • Disable or deactivate the plugin immediately:
     • In WordPress admin: Plugins → deactivate Assistant for NextGEN Gallery
     • Via WP‑CLI:

       wp plugin deactivate assistant-for-nextgen-gallery
                   

     • Or rename the plugin folder via SFTP: wp-content/plugins/assistant-for-nextgen-gallery → assistant-for-nextgen-gallery.disabled
   • Restrict access to the site:
     • Enable maintenance mode
     • If possible, restrict access by IP to admin endpoints until the site is secured.
2. Block the vulnerable endpoints at the server or WAF level
   • If you have a WAF, create a temporary rule to block requests to the plugin’s endpoints or any request containing directory traversal patterns (../ and URL‑encoded variants).
   • If you don’t have a WAF, use server-level rules (nginx/apache) to return 403 for requests that match traversal patterns (see conceptual rules below).
3. Preserve evidence
   • Snapshot the server and file system before making changes that would lose forensic data.
   • Export webserver logs, PHP logs, and WordPress debug logs.
4. Validate backups and prepare restoration plan
   • Verify offsite backups (date and integrity).
   • If backups are intact and recent, plan a staged restore.
5. Scan the site
   • Perform a malware scan (ideally from a trusted host or offline copy). Do not rely solely on WordPress plugin scanners on a potentially compromised site.
   • Look for webshells, unknown files, changed file permissions, or modified .htaccess.
6. Rotate secrets
   • Rotate admin passwords and any credentials stored in the database or files if compromise is suspected.
7. Notify stakeholders
   • Inform hosting provider, development team, and affected customers/owners if required by policy or regulation.
8. Monitor
   • Tighten monitoring: watch for repeated scans, repeated blocked attempts, or new anomalies.

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Long‑term remediation and secure configuration

Once the immediate danger is mitigated, follow these steps to harden your site:

1. Replace or update the plugin
   • Monitor the plugin vendor for an official fix.
   • If the vendor does not respond in a reasonable time, consider removing the plugin permanently or replacing it with a well-maintained alternative.
2. Harden file and folder permissions
   • Limit write permissions for the webserver user:
     • wp-content/tải lên and plugin folders need write access; reduce permissions to the minimum necessary, e.g., 755 for directories and 644 for files, avoiding global write permissions.
   • Store backups offsite with restricted access.
3. Implement principle of least privilege
   • Avoid running scheduled tasks with elevated privileges that could be manipulated.
4. Continuous scanning and monitoring
   • Implement file integrity monitoring to detect unexpected deletions.
   • Regularly review logs and set alerts for traversal-like requests.
5. Keep WordPress core, themes, and plugins updated
   • Apply updates in a staging environment and test before production.
6. Backups and restore testing
   • Maintain multiple backup retention points.
   • Periodically perform test restores to ensure reliability.
7. Security development lifecycle for custom code
   • If you run custom plugins or themes, use secure coding practices (validate inputs, sanitize paths, avoid direct filesystem operations based on user input).

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How WP‑Firewall protects you (overview from our perspective)

At WP‑Firewall we treat vulnerabilities like this with a layered defensive model:

1. Virtual patching (vPatch)
   • We deploy WAF rules that stop exploitation patterns at the edge, blocking requests that attempt path traversal or unauthorized file operations. Virtual patching buys time until an official vendor patch is available.
2. Positive & negative filtering
   • Positive model: allow only expected values (whitelisting) for plugin endpoints where possible.
   • Negative model: block known bad constructs: ../ sequences, overly long path segments, unusual HTTP verbs to plugin endpoints, or URL-encoded traversal.
3. Rate limiting and bot protection
   • Automated scanners and bots generate high volume. Rate limiting slows down or stops mass automated exploitation attempts.
4. File integrity monitoring and alerts
   • WP‑Firewall can detect sudden deletions or modifications and alert the admin to take recovery action.
5. Behavior-based detection
   • Patterns that show an attempt to delete multiple directories in a short time are flagged as high risk and blocked.
6. Safe remediation guidance
   • For customers, we provide step-by-step incident response guidance and, when necessary, assist in recovery operations.
7. Managed blacklist/whitelist features
   • Admins can temporarily blacklist offending IPs or whitelist trusted operator IPs while remediation is ongoing.

If you already use WP‑Firewall, our systems will identify and block exploitation attempts for this vulnerability via our latest rule set. If you do not, consider immediate protection (see sign-up paragraph below).

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Suggested virtual patch / WAF rule patterns (conceptual — do not implement blindly)

Below are conceptual patterns we use to detect exploitation attempts. They are intentionally descriptive rather than exact rule code to avoid providing attacker instruction.

• Block requests where path or query parameters contain:
  • Traversal sequences: “../”, “..%2f”, “%2e%2e%2f”, and similar encodings.
  • Null bytes or other suspicious encodings near file path tokens.
• Block requests to plugin-specific entrypoints if the request:
  • Uses HTTP methods not expected (e.g., DELETE where plugin only expects GET/POST).
  • Contains filenames or directory paths in parameters that contain traversal sequences.
• Block rapid sequences of file operation requests originating from the same IP or User-Agent.
• Whitelist known management IPs and block the rest from accessing plugin admin endpoints.

Example conceptual nginx snippet (non‑executable guidance):

# Deny obvious traversal attempts anywhere in the request
if ($request_uri ~* "(%2e%2e|%2f%2e|%2e%2f|\.\./)") {
    return 403;
}
# Additional server-level restrictions: protect WP plugin endpoints
location ~* /wp-content/plugins/assistant-for-nextgen-gallery/ {
    # allow internal admin IPs only (replace with your IP)
    allow 203.0.113.5;
    deny all;
}

Important: Test rules carefully in staging first. Blocking too aggressively can break legitimate functionality.

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Incident response playbook — step‑by‑step if you detect exploitation

1. Isolate
   • Immediately block the offending IP(s) at the firewall or WAF.
   • Put the site into maintenance mode.
2. Preserve evidence
   • Snapshot disk, export logs, and take a full backup of the current state before making further changes.
3. Assess damage
   • Identify which directories and files have been deleted or modified.
   • Check offsite backups and determine the most recent clean restore point.
4. Clean and restore
   • If site integrity is compromised beyond simple file deletion, perform a full restore from a known-good backup.
   • If only media or plugin folders were affected and backups are available, restore those specific paths.
5. Remediate root causes
   • Deactivate the vulnerable plugin and replace or remove it.
   • Patch the vulnerability when vendor releases an update; apply vendor update and test.
6. Strengthen defenses
   • Deploy WAF virtual patching and custom rules blocking traversal patterns.
   • Tighten server file permissions and rotating credentials.
7. Post‑incident communication
   • Notify stakeholders and customers if required under your policies or regulatory obligations.
   • Document incident timeline and containment steps.
8. Lessons learned
   • Update your incident playbooks, testing and monitoring schedules, and vendor/product decisions based on the event.

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For plugin authors: secure coding notes to prevent path traversal and destructive filesystem operations

If you maintain a plugin, this vulnerability underscores common mistakes. Best practices:

• Never perform filesystem delete operations based directly on user-controlled inputs.
• Normalize and canonicalize file paths before performing operations (realpath) and check that the result resides inside an allowed base directory.
• Use strict whitelists: accept only filenames or identifiers, then map to server-side safe paths (do not accept raw paths).
• Validate and sanitize: strip path separators, reject encoded traversal tokens, reject NULL bytes.
• Implement capability checks: limit file deletion operations to authenticated, authorized users and verify nonces.
• Implement a safety net: move deletions to a quarantine area rather than permanent unlink when possible.
• Test your plugin against common path traversal test cases and add unit/integration tests.
• Provide an emergency disclosure channel and rapid patching process for security reports.

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Closing recommendations — a prioritized checklist

If your site uses the affected plugin (Assistant for NextGEN Gallery <= 1.0.9):

1. Immediately deactivate or remove the plugin.
2. Block plugin endpoints and traversal patterns at server/WAF level.
3. Validate and secure backups; prepare to restore as needed.
4. Check logs for suspicious requests and preserve them for investigation.
5. If you host multiple sites, schedule an audit across all instances.
6. Consider deploying a WAF with virtual patching capability to block attempts while you remediate.
7. Keep your incident response and backup procedures tested and up‑to‑date.

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Protect your WordPress site now with WP‑Firewall Basic (Free)

Protecting your WordPress site requires both proactive and reactive controls. To help you quickly defend against risks like CVE‑2025‑7641, WP‑Firewall offers a free Basic plan that includes essential managed firewall protection, unlimited bandwidth, a WAF, malware scanning, and mitigation for OWASP Top 10 risks. This plan lets you deploy virtual patching, file integrity monitoring, and immediate blocking rules that stop exploitation attempts while you remediate.

Sign up for the WP‑Firewall Basic (Free) plan and get immediate managed WAF protection and malware scanning: https://my.wp-firewall.com/buy/wp-firewall-free-plan/

(If you need more advanced features — automatic malware removal, IP blacklisting/whitelisting, monthly security reports, or auto virtual patching — review our paid tiers.)

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Final thoughts

This vulnerability is a reminder that plugins that interact with the filesystem require careful input validation and privilege separation. Unauthenticated destructive abilities are especially dangerous because they allow automated mass exploitation.

Take the steps above immediately if you run the affected plugin. If you manage multiple client sites, treat this as a high-priority patch window for all sites under your care.

If you want assistance implementing WAF rules, performing a safe forensic analysis, or restoring a site from backups, WP‑Firewall’s security team can help. Our focus is to minimize downtime, prevent lateral damage, and restore services safely.

Stay safe, keep backups tested, and act quickly — a few proactive minutes now can prevent hours or days of recovery work later.

— WP‑Firewall Security Team

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