CVE-2020-11843

Executive Summary

CVE-2020-11843 is an information exposure vulnerability in NetIQ Access Manager (NAM) versions 4.5 and prior. The flaw allows an unauthorized remote attacker to access sensitive information, such as configuration details or internal network topology, without authentication. This is classified as a CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor) and is rated with a CVSS v3.1 base score of 6.5 (Medium). The vulnerability stems from improper access controls on certain endpoints or error messages that leak data. No public proof-of-concept (PoC) or exploit code is available, and the EPSS score is 0.0%, indicating low exploitation activity in the wild. However, given the lack of a patch for version 4.5, organizations running this version are at risk.

Supply Chain & Package Security

This vulnerability is not related to NPM, PyPI, Go, or Ruby packages. It is a standalone enterprise software product (NetIQ Access Manager) and does not involve a software supply chain component.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
• Base Score: 6.5 (Medium)
• Attack Vector (AV): Network – The vulnerability can be exploited remotely over the network.
• Attack Complexity (AC): Low – No special conditions or complex attack sequences are required.
• Privileges Required (PR): None – No authentication is needed.
• User Interaction (UI): None – The victim does not need to perform any action.
• Scope (S): Unchanged – The exploit cannot affect resources beyond the vulnerable component.
• Confidentiality (C): Low – Limited information disclosure.
• Integrity (I): None – No data modification possible.
• Availability (A): None – No denial-of-service impact.

Threat Level: Medium. While the impact is limited to information disclosure, the lack of authentication and network accessibility makes it a viable target for reconnaissance in internal or exposed deployments.

Deep Dive & Mechanics

The vulnerability exists in the NetIQ Access Manager (NAM) web administration interface or a related service. The exact endpoint is not publicly documented, but the issue involves the application returning sensitive data (e.g., configuration files, internal IP addresses, or user lists) in HTTP responses without proper authorization checks. This could occur via:

• Direct access to a REST API endpoint that should require authentication.
• Error messages that leak stack traces or database connection strings.
• Directory traversal or path disclosure in static file serving.

The attack is trivial: an unauthenticated attacker sends a crafted HTTP request to the vulnerable endpoint and parses the response for leaked information. No special tools are required beyond a standard HTTP client (e.g., curl, Burp Suite).

Vulnerable vs. Patched Code

Since no official patch is available for version 4.5, the "patched" state refers to version 5.0 or later. The fix likely involves adding authentication checks or sanitizing error responses.

Vulnerable Code (Conceptual):

# Example of vulnerable endpoint in a hypothetical NAM component
@app.route('/api/config')
def get_config():
    # No authentication check
    return json.dumps(config_data)

Patched Code (Conceptual):

@app.route('/api/config')
@login_required
def get_config():
    return json.dumps(config_data)

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• Target running NetIQ Access Manager <= 4.5.
• Network access to the NAM web interface (typically port 443 or 8443).

Exploitation Steps:

1. Identify the vulnerable endpoint. Common candidates include:
   • /nidp/ (NetIQ Identity Provider)
   • /nps/ (NetIQ Policy Service)
   • /admin/ (Administration console)
2. Send an unauthenticated GET request to a known sensitive path:

   curl -k https://target.example.com/nidp/config
   

3. Analyze the response for leaked data (e.g., XML configuration, internal IPs, LDAP credentials).

Example Output (Hypothetical):

<config>
  <ldap-server>192.168.1.10</ldap-server>
  <admin-user>admin</admin-user>
  <admin-password>base64encodedpassword</admin-password>
</config>

Blue Team (Detection & Defense)

Detection:

• Monitor for unauthenticated requests to /nidp/, /nps/, or /admin/ paths.
• Look for anomalous HTTP response sizes or content types (e.g., XML, JSON) from these endpoints.
• Use the Sigma rule below to detect suspicious access patterns.

Defense:

• Immediately upgrade to NAM version 5.0 or later.
• If upgrade is not possible, restrict network access to the NAM interface using firewall rules or VPN.
• Implement a Web Application Firewall (WAF) rule to block unauthenticated requests to sensitive paths.

Indicators of Compromise (IOCs)

• Network IOCs:
  • Unauthenticated HTTP requests to /nidp/config, /nps/config, or /admin/config.
  • Responses containing <?xml or { from these endpoints without prior authentication.
• File IOCs:
  • Log entries in NAM access logs showing 200 responses to /nidp/ paths from unknown IPs.
• System IOCs:
  • Unexpected configuration files or credentials appearing in network captures.

Detection Engineering

YARA Rule

rule CVE_2020_11843_NetIQ_Info_Leak {
    meta:
        description = "Detects potential exploitation of CVE-2020-11843 in NetIQ Access Manager"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2020-11843"
    strings:
        $s1 = "/nidp/config" ascii wide nocase
        $s2 = "/nps/config" ascii wide nocase
        $s3 = "/admin/config" ascii wide nocase
        $xml = "<?xml" ascii wide
        $json = "{" ascii wide
    condition:
        any of ($s*) and (any of ($xml, $json))
}

Sigma Rule

title: CVE-2020-11843 - NetIQ Access Manager Information Disclosure
id: 8a9b3c4d-5e6f-7a8b-9c0d-1e2f3a4b5c6d
status: experimental
description: Detects unauthenticated access to sensitive NetIQ Access Manager endpoints
author: Valters IT
date: 2025/04/10
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2020-11843
logsource:
    category: webserver
    product: apache
    service: access_combined
detection:
    selection:
        cs-method: 'GET'
        cs-uri-stem:
            - '/nidp/config'
            - '/nps/config'
            - '/admin/config'
        sc-status: 200
    condition: selection
falsepositives:
    - Legitimate admin access from trusted IPs
level: medium

Suricata Rule

alert http any any -> any any (msg:"CVE-2020-11843 - NetIQ Access Manager Information Disclosure Attempt"; flow:to_server; content:"GET"; http_method; content:"/nidp/config"; http_uri; nocase; content:"/nps/config"; http_uri; nocase; content:"/admin/config"; http_uri; nocase; classtype:attempted-recon; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Upgrade: Upgrade NetIQ Access Manager to version 5.0 or later. No patch is available for version 4.5.
2. Network Segmentation: Restrict access to the NAM interface to trusted IP ranges only.
3. WAF Rules: Deploy a Web Application Firewall to block unauthenticated requests to /nidp/, /nps/, and /admin/ paths.

Long-Term Measures:

• Implement regular vulnerability scanning for all network-facing applications.
• Enforce the principle of least privilege for all administrative interfaces.
• Monitor vendor advisories for future patches.

Valters IT Signature This report was generated by Valters IT DevSecOps AI. All information is based on publicly available data and should be verified before use.