Pluginnaam	Solace Extra
Type of Vulnerability	SSRF
CVE Number	CVE-2025-58203
Urgentie	Laag
CVE Publish Date	2025-08-27
Source URL	CVE-2025-58203

Solace Extra <= 1.3.2 — SSRF (CVE-2025-58203): What WordPress site owners need to know and how to protect themselves

Datum: 27 August 2025
Auteur: WP‑Firewall Security Team

Samenvatting: A Server‑Side Request Forgery (SSRF) vulnerability was reported in the Solace Extra WordPress plugin affecting versions <= 1.3.2 (fixed in 1.3.3). The flaw allows an authenticated administrator to cause the site to perform HTTP requests to arbitrary destinations — including internal network resources — potentially exposing sensitive data or enabling further attacks. CVSS 4.4 (Low), CVE‑2025‑58203.

This post explains what SSRF is, how this specific issue affects WordPress sites, exploitation scenarios, detection and containment steps, detailed mitigations you can apply immediately (including WAF rules and network controls), and longer‑term hardening guidance. Where relevant we explain how WP‑Firewall can help protect your site now and going forward.

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What is SSRF and why it matters for WordPress

Server‑Side Request Forgery (SSRF) is a class of vulnerability where an attacker can make a vulnerable server send HTTP (and other protocol) requests to arbitrary URIs. Instead of the attacker directly connecting to a target host, the attacker controls a parameter that a server then uses to fetch or relay data. When that server sits inside a protected network (for example behind a firewall, on localhost, or on a cloud metadata service), SSRF can be used to reach internal endpoints not normally exposed to the internet.

Why SSRF matters in WordPress:

• Many plugins accept user input that results in server‑side HTTP requests (fetching remote images, webhooks, previews, embeds, URL fetchers, APIs). If that input is not strictly validated, SSRF becomes possible.
• WordPress often runs in hosting environments where internal services (database management interfaces, metadata APIs, cloud services, admin panels) are available on internal addresses. SSRF can be a path to harvest secrets or pivot laterally.
• Even if initial impact seems limited (e.g., the vulnerability requires an administrator account), administrator accounts are commonly compromised through phishing, stolen credentials, or reused passwords. Any path that amplifies the attacker’s reach is serious.

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The Solace Extra issue in brief

• Affected software: Solace Extra WordPress plugin
• Kwetsbare versies: <= 1.3.2
• Vastgesteld in: 1.3.3 (upgrade recommended)
• CVE: CVE‑2025‑58203
• Severity (reported): Low, CVSS 4.4
• Vereiste privilege: Administrator
• Discovery credit: security researcher who reported responsibly

The plugin accepted input that could be used by the application to perform HTTP(S) requests without adequate validation of the target destination. Because the feature was accessible to administrators, an attacker who already has an elevated account can make the site fetch attacker‑controlled URLs — including internal network addresses — resulting in SSRF.

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Realistic exploitation scenarios

Understanding realistic scenarios helps prioritize response and mitigation.

1. Privileged insider or compromised admin account:
   • If an attacker already controls an admin account (phished credentials, reused passwords, or malicious admin), they can trigger SSRF to enumerate internal services (e.g., 127.0.0.1:3306, cloud metadata endpoints 169.254.169.254, internal management interfaces).
   • The attacker might retrieve tokens, service‑account secrets, or sensitive endpoints that simplify further attacks.
2. Secondary attack via social engineering:
   • If a developer, agency, or site manager with admin access is tricked into performing plugin actions that internally fetch a malicious URL, an attacker could still leverage SSRF without direct admin credential theft.
3. Local network or cloud metadata access:
   • Cloud metadata endpoints (AWS, GCP, Azure) often return credentials or instance data. SSRF may allow the attacker to read those endpoints and escalate privileges externally.
   • Access to internal management consoles (phpMyAdmin, Solr, Elasticsearch, etc.) may reveal credentials or expose additional remote code execution paths.
4. Information disclosure and fingerprinting:
   • SSRF can be used to discover internal network topology, open ports, and services, which assists in planning a full compromise.

Note: The vulnerability requires administrative privileges to trigger in this case, which limits remote unauthenticated exploitation. However, because admin accounts are a high-value target and compromise of admin often happens, we must treat SSRF responsibly and patch/mitigate quickly.

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Immediate steps every site owner should take (ordered)

1. Upgrade first
   • Update Solace Extra to version 1.3.3 or later immediately. This is the simplest and most reliable fix.
2. If you cannot upgrade right away, temporarily deactivate the plugin
   • Disable the plugin from the WordPress admin (Plugins → Installed Plugins) until the site can be safely updated.
3. Audit administrator accounts
   • Review the list of administrator users. Remove any unknown users and rotate passwords for admin accounts (use strong unique passwords).
   • Enforce two‑factor authentication (2FA) for administrators if possible.
4. Check logs for suspicious activity
   • Look for admin actions around the plugin (times, IP addresses, unusual parameters). Check web server access logs, PHP error logs, and WordPress activity logs (if available).
   • Search for requests that include unusual or external URLs passed to plugin endpoints.
5. Run a malware scan
   • Perform a full site scan for webshells and suspicious files. If you suspect compromise, consider a professional incident response.
6. Review outgoing network access
   • If feasible, apply host egress rules or firewall rules to block unexpected outbound connections from the web server to internal IP ranges and cloud metadata IPs.
7. Notify your team and hosting provider
   • Let your hosting provider know if you detect suspicious activity. They can help isolate the server, snapshot disks, and gather forensic evidence.

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Detection: what to look for (indicators of potential SSRF usage)

• Web server access logs showing backend requests triggered via the plugin endpoints that contain parameters with URLs or IP addresses (e.g., ?url= or ?fetch= values).
• Requests that include internal IP addresses (127.0.0.1, 169.254.169.254, 10.x.x.x, 172.16.x.x–172.31.x.x, 192.168.x.x) in parameters or payloads.
• Unexpected outbound connections from the web server to internal ports and addresses — check firewall/eBPF/netstat records.
• WP cron jobs or scheduled tasks making unexpected external calls.
• New or modified files in wp‑content or wp‑uploads that could be webshells used in a later stage.
• Login attempts, password resets, or 2FA bypass attempts preceding plugin actions — this could indicate account takeover.

Example log search queries:
Apache/nginx: grep -i "solace" access.log | grep -E "url=|fetch=|target="
Search for internal IPs in logs: grep -E "169\.254\.169\.254|127\.0\.0\.1|10\.[0-9]+\.[0-9]+\.[0-9]+|172\.1[6-9]\.|172\.2[0-9]\.|172\.3[0-1]\.|192\.168\." access.log

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Network and host‑level mitigations

Even after upgrading, putting proper egress controls in place significantly reduces SSRF blast radius.

1. Egress filtering
   • Block or limit outbound HTTP/S from the web server to internal IP ranges and known cloud metadata endpoints at the host or network firewall. Only allow outbound access to required third‑party APIs.
   • Example: deny outbound traffic to 169.254.169.254 (cloud metadata) from the web server user.
2. Block internal ranges from HTTP client libraries
   • At application level or via a WAF, disallow requests where parameters resolve to internal IPs or RFC1918 addresses.
3. Use an instance metadata protection mechanism (cloud-specific)
   • For cloud servers, enable metadata service protection features (IMDSv2 on AWS, or similar protections on other clouds).
4. Host hardening
   • Ensure PHP, WordPress core, and all plugins/themes are up to date.
   • Run the application under a user with minimal privileges (no direct root).
   • Restrict filesystem permissions to prevent PHP from writing to executable locations.

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WAF and virtual patching: how WP‑Firewall protects you now

WP‑Firewall’s managed WAF can provide near‑immediate protections while you prepare the upgrade and harden the environment.

What WP‑Firewall can do for this SSRF:

• Deploy a virtual patch (WAF rule) that identifies and blocks HTTP request attempts that include attacker‑controlled URLs or payloads targeted at internal/risky addresses.
• Block requests to known internal address patterns and cloud metadata endpoints when they appear as parameter values or in request bodies.
• Monitor and alert on suspicious admin endpoint activity (e.g., plugin AJAX endpoints being used with URL parameters).
• Provide scheduled malware scans and file integrity checks to detect post‑exploit artifacts.

Suggested WAF rule logic (conceptual):

• Block admin requests that include URL parameters that resolve to internal IPs or private ranges.
• Block any request parameter containing 169.254.169.254 or other cloud metadata patterns.
• Block outbound URL fetching patterns where the destination host matches RFC1918 address spaces.

Example generic rule (conceptual pseudo‑signature):
If request path matches plugin admin endpoint AND request body or query string contains ((http(s)?://)?(127\.0\.0\.1|169\.254\.169\.254|10\.\d{1,3}\.\d{1,3}\.\d{1,3}|172\.(1[6-9]|2[0-9]|3[0-1])\.\d{1,3}\.\d{1,3}|192\.168\.\d{1,3}\.\d{1,3})) => block and log.

If you manage your own ModSecurity/WAF, here’s an illustrative ModSecurity rule (adapt to your environment — this is an example to get started):

# Block SSRF attempts with internal or metadata IPs in parameters
SecRule ARGS|REQUEST_BODY|QUERY_STRING "@rx (169\.254\.169\.254|127\.0\.0\.1|10\.\d{1,3}\.\d{1,3}\.\d{1,3}|172\.(1[6-9]|2[0-9]|3[0-1])\.\d{1,3}\.\d{1,3}|192\.168\.\d{1,3}\.\d{1,3})" \
    "id:1009001,phase:2,deny,log,msg:'Potential SSRF attempt - internal address in request',severity:2"

Important: tune rules to avoid false positives on legitimate use cases. WP‑Firewall’s managed ruleset includes tuning to minimize disruption while maximizing protection.

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Detailed remediation checklist

1. Upgrade plugin to 1.3.3 or later immediately.
2. If upgrade is not possible:
   • Deactivate plugin.
   • Apply WAF rule(s) blocking internal addresses and metadata IPs in parameters.
3. Enforce admin security:
   • Force password reset for administrators.
   • Enforce strong passwords and 2FA.
   • Audit user accounts and remove unnecessary admins.
4. Harden outbound connectivity:
   • Apply egress rules to prevent server from contacting internal or cloud metadata IPs.
5. Perform a full site and server audit:
   • Scan for webshells, changed files, and suspicious cron jobs.
   • Review recent uploads and PHP files in wp‑content.
6. Rotate any keys or tokens discovered on the server (database credentials, API keys).
7. If you detect compromise:
   • Isolate the server (remove from load balancer, freeze access).
   • Take forensic snapshots (disk, memory if possible) before making changes.
   • Restore from a known‑good backup if necessary after cleaning.
8. Log and monitoring:
   • Enable and retain logs (access, error, firewall logs) for at least 90 days where possible.
   • Configure alerts for blocked WAF rules and admin endpoint anomalies.

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If you suspect a compromise — incident response steps

1. Contain
   • Immediately isolate the affected server (take it off the network or behind maintenance controls).
   • Disable the vulnerable plugin if not already done.
2. Preserve evidence
   • Take disk images and capture current memory if feasible. Preserve logs and configuration snapshots.
3. Triage
   • Identify indicators of compromise (webshells, new admin users, suspicious scheduled tasks).
4. Eradicate
   • Remove backdoors and malicious files. Reinstall WordPress core and plugins from clean sources.
   • Rebuild the server if deeper persistence is suspected.
5. Recover
   • Restore from a clean backup and apply all patches.
   • Rotate credentials (database, API keys) and revoke tokens that could be exposed.
6. Post‑incident
   • Conduct a root cause analysis and implement controls to prevent recurrence (WAF rules, egress filtering, 2FA).
   • Consider external security review if the incident was severe.

If you’re using a managed security provider or have a dedicated security plan, notify them immediately for assistance.

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Developer guidance — secure coding patterns to prevent SSRF

If your team is building or maintaining plugins that perform server‑side HTTP requests, adopt the following patterns:

1. Prefer allow‑list over block‑list
   • Validate destination hosts against a strict allow‑list of permitted domains or services. Never rely solely on blacklist checks.
   • For admin‑facing features, avoid arbitrary URL fetching unless necessary.
2. Resolve and validate IPs
   • Resolve hostnames and disallow requests that resolve to internal IP ranges (RFC1918, link‑local, loopback) or cloud metadata addresses.
   • Validate both DNS and IP (watch for DNS rebinding).
3. Restrict protocol and response handling
   • Limit protocols to HTTP/HTTPS and disallow file://, gopher://, ftp:// unless explicitly required.
   • Limit the size of responses and timeout durations.
4. Sanitize input carefully
   • Normalize input and reject suspicious characters, redirects, or encoded IP values (e.g., 0x7f000001 for 127.0.0.1).
   • Enforce URL parsing libraries that provide consistent resolution and validation.
5. Least privilege
   • Run HTTP client calls under contexts with minimal filesystem/network privileges.
   • Avoid exposing sensitive tokens to plugin settings where they can be leaked in logs or external requests.
6. Logging and alerts
   • Log attempts to fetch external resources and alert when requests target IP ranges outside expected domains.

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Practical detection rules you can add to your logs/WAF

• Alert when an admin endpoint receives a query parameter containing an IPv4/IPv6 or metadata URL pattern.
• Alert on outbound connection attempts from the PHP process to internal IPs or the cloud metadata IP.
• Create a rate‑limited alert for repeated admin actions that include URL fetch parameters (this often indicates automated enumeration).

Example regex for matching private IPv4 addresses in web requests:

\b(127\.0\.0\.1|10\.(?:[0-9]{1,3}\.){2}[0-9]{1,3}|172\.(?:1[6-9]|2[0-9]|3[0-1])\.(?:[0-9]{1,3}\.)[0-9]{1,3}|192\.168\.(?:[0-9]{1,3}\.)[0-9]{1,3}|169\.254\.169\.254)\b

Tune and test these regexes in a staging environment to reduce false positives.

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Why plugin updates alone aren’t enough

Patching the plugin fixes the code path, but consider the following:

• If an attacker used SSRF earlier to extract internal tokens or credentials, those secrets may already be compromised. Rotate them.
• Attacker may have dropped persistence mechanisms (webshells, cron jobs) that need removal.
• Future vulnerabilities are inevitable. Layered defenses (WAF, egress filtering, strong account controls) reduce the chance that a new vulnerability leads to compromise.

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Long‑term hardening and best practices

1. Principle of least privilege
   • Limit number of administrators. Use granular roles instead of giving admin to many users.
2. Enforce 2FA for privileged accounts
   • Reduce risk from credential reuse or phishing.
3. Server isolation and egress control
   • Restrict what your web server can reach outside the network — only allow necessary API endpoints.
4. Timely updates and plugin hygiene
   • Remove unused plugins and themes. Subscribe to security alerts and apply updates quickly.
5. Continuous monitoring
   • Keep a WAF active, retain logs, and monitor for anomalous admin activity.
6. Periodic security reviews
   • Code audit high‑risk plugins and schedule regular penetration tests.

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Example post‑upgrade checklist (what to verify after upgrading to 1.3.3)

• Plugin version shows 1.3.3 or later in Plugins admin screen.
• Clear any caches and test the feature path that performs URL fetches with safe known hosts.
• Run a WAF with SSRF detection rules enabled to look for any remaining exploit attempts.
• Rotate critical credentials and API tokens if there’s any suspicion of previous exploitation.
• Perform a post‑upgrade scan for suspicious files and scheduled tasks.

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Real world note from our incident desk

In our experience, SSRF cases that require administrator privileges are less likely to be exploited en masse than unauthenticated vulnerabilities — but they are still high‑impact when they occur because an attacker with admin privileges combined with SSRF can move quickly. In several engagements we’ve seen SSRF used to access cloud metadata services to extract short‑lived credentials and then use those to spin up further resources or exfiltrate data. Preventing that chain requires both application‑level fixes and network controls.

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Closing thoughts

The Solace Extra SSRF (CVE‑2025‑58203) is a reminder that even admin‑only functionality can present a serious risk. Attackers often combine seemingly low‑severity issues with other control failures (weak passwords, lack of 2FA, permissive egress rules) to escalate into full compromise. The fastest effective response is a layered approach:

• Apply the vendor patch (upgrade plugin to 1.3.3+) immediately.
• Use a WAF and egress filtering as compensating controls while you patch and verify.
• Harden admin access and rotate credentials where needed.
• Monitor logs, scan for signs of compromise, and have an incident response plan ready.

If you’d like help implementing WAF rules, egress controls, or a vulnerability response plan, our WP‑Firewall team is available to assist — from free onboarding with the Basic plan to managed virtual patching in our higher tier plans. Security is a process; the most secure sites are the ones that combine timely patching with strong architecture and vigilant monitoring.

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Resources and quick references

• Affected plugin: Solace Extra — upgrade to 1.3.3 or later.
• CVE: CVE‑2025‑58203
• Recommended immediate actions: upgrade, deactivate if necessary, enforce admin security, enable WAF rules blocking internal addresses.
• WP‑Firewall Basic (Free) plan: https://my.wp-firewall.com/buy/wp-firewall-free-plan/

Stay safe and proactive — treat SSRF like any other avenue into your internal resources, and you’ll reduce the chances of a small weakness becoming a big breach.