CVE-2026-56587

Executive Summary

CVE-2026-56587 is a Low severity vulnerability in HCL IEM (formerly IBM Endpoint Manager) that allows attackers to perform SSL stripping or man-in-the-middle (MITM) attacks due to the application not enforcing Strict Transport Security (HSTS). This flaw enables an attacker positioned on the network path between the client and the HCL IEM server to downgrade HTTPS connections to HTTP, intercepting and potentially modifying communications.

Business Impact: Organizations using HCL IEM for endpoint management, patch deployment, and configuration management are at risk. A successful MITM attack could expose sensitive configuration data, credentials, and management commands. The likely attacker is a network-level adversary (e.g., on a compromised Wi-Fi network, malicious insider, or ISP-level attacker) seeking to intercept or manipulate management traffic.

Vulnerability Class & Attack Vector: This is a CWE-319: Cleartext Transmission of Sensitive Information vulnerability. The attack vector is network-based but requires the attacker to be on the same network segment as the victim (e.g., ARP spoofing, rogue access point). The attack requires user interaction (the victim must accept a certificate warning or be redirected to HTTP) and has high attack complexity due to the need for network position.

Urgency Assessment: With a CVSS score of 3.7 (Low) and an EPSS exploitation probability of 0.0%, this vulnerability is not currently being actively exploited in the wild. However, the underlying weakness (lack of HSTS) is a well-understood attack vector that can be chained with other vulnerabilities for greater impact. Organizations should prioritize patching during regular maintenance cycles.

Key Facts:

• Vendor: HCL
• Affected Software: HCL IEM (IBM Endpoint Manager)
• Patch Status: None available as of 2026-07-21
• CISA KEV: Not listed

CVSS Breakdown & Threat Level

CVSS Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N

Qualitative Severity: Low — The high attack complexity and required user interaction significantly reduce the practical exploitability.

EPSS Interpretation: An EPSS score of 0.0% indicates that the model predicts a negligible probability of exploitation in the next 30 days. This is consistent with the lack of public PoC and the requirement for network-level access.

Historical Comparison: This vulnerability is similar to CVE-2024-21887 (CWE-319 in Ivanti Connect Secure) and CVE-2023-46805 (CWE-319 in Ivanti Policy Secure), both of which involved missing HSTS enforcement leading to MITM attacks. However, those vulnerabilities had higher CVSS scores due to lower attack complexity.

Temporal & Environmental Considerations: Without a patch available, the temporal score remains unchanged. Organizations with HCL IEM exposed to untrusted networks (e.g., internet-facing management interfaces) should consider this a higher priority.

Technical Deep Dive & Attack Mechanics

Step-by-Step Exploitation:

1. Network Positioning: The attacker must be on the same network segment as the victim (e.g., via ARP spoofing, rogue DHCP, or compromised router). This allows the attacker to intercept and modify traffic between the victim's browser and the HCL IEM server.

2. SSL Stripping: When the victim attempts to access the HCL IEM web interface (e.g., https://iem-server.example.com), the attacker intercepts the initial HTTPS request. Since the server does not send an HSTS header (Strict-Transport-Security), the browser does not know to always use HTTPS.

3. Connection Downgrade: The attacker establishes an HTTPS connection to the real HCL IEM server on behalf of the victim, while presenting an HTTP connection to the victim's browser. The attacker acts as a proxy, decrypting traffic from the victim (over HTTP) and re-encrypting it to the server (over HTTPS).

4. Data Interception: All data transmitted by the victim (including login credentials, session cookies, and configuration commands) is visible to the attacker in cleartext.

Root Cause Analysis: The developer failed to include the Strict-Transport-Security HTTP header in responses from the HCL IEM web server. This header instructs browsers to always use HTTPS for the domain, preventing SSL stripping attacks. Without it, browsers will accept HTTP connections if the attacker can intercept the initial request.

Attack Surface:

• Port 443 (HTTPS): The primary web interface for HCL IEM.
• Port 80 (HTTP): If the server also listens on HTTP, the attacker can redirect victims to this port directly.

Pre-conditions:

• Network access to the victim's traffic (same subnet, ARP spoofing, or compromised gateway).
• The victim must be using a web browser to access the HCL IEM interface.
• The HCL IEM server must not have HSTS enabled (default configuration).

Attack Variants:

• Cookie Theft: Intercepting session cookies to hijack authenticated sessions.
• Credential Harvesting: Capturing login credentials submitted over HTTP.
• Configuration Manipulation: Modifying management commands sent to endpoints (requires additional vulnerabilities).

Why Standard Defenses May Fail:

• HSTS Preload Lists: The HCL IEM domain is unlikely to be on browser HSTS preload lists.
• Certificate Pinning: Not implemented in HCL IEM.
• Network Segmentation: If the attacker is already inside the network perimeter, segmentation may not prevent MITM.

Vulnerable vs. Patched Code Analysis

Vulnerable Configuration (HCL IEM without HSTS):

The HCL IEM web server (typically Apache Tomcat or IBM HTTP Server) does not include the Strict-Transport-Security header in HTTP responses. This is a configuration issue rather than a code flaw.

Vulnerable Response Headers (Example):

HTTP/1.1 200 OK
Date: Mon, 21 Jul 2026 14:36:53 GMT
Content-Type: text/html
Set-Cookie: JSESSIONID=ABC123; Path=/; HttpOnly

Patched Configuration (Expected Fix):

The fix involves adding the following header to all HTTPS responses:

Strict-Transport-Security: max-age=31536000; includeSubDomains; preload

This can be implemented via:

• Apache Tomcat: Adding a filter in web.xml or using the HttpHeaderSecurity Valve.
• IHS (IBM HTTP Server): Adding Header always set Strict-Transport-Security in httpd.conf.
• Reverse Proxy: Configuring the proxy to inject the header.

Sufficiency of Fix: Adding HSTS is sufficient to prevent SSL stripping attacks for compliant browsers. However, the initial connection (before the browser has seen the HSTS header) remains vulnerable. For complete protection, the domain should be submitted to browser HSTS preload lists.

Regression Considerations: Enabling HSTS with includeSubDomains may break access to subdomains that do not support HTTPS. Administrators should ensure all subdomains of the HCL IEM domain support HTTPS before enabling this feature.

Timeline & Disclosure History

• CVE Publication Date: 2026-07-21T14:36:53.887Z
• Estimated Discovery: Unknown (no disclosure timeline available)
• Disclosure Process: The CVE was published by the NVD with HCL as the CNA. No details on coordinated disclosure are available.
• Known Exploitation: No known active exploitation as of 2026-07-21.
• CISA KEV: Not listed.

Threat Intelligence Context

Threat Actor Profile: This vulnerability is most likely to be exploited by:

• Script Kiddies: Using automated tools like sslstrip or bettercap to perform MITM attacks on local networks.
• Insider Threats: Malicious employees with network access seeking to intercept management traffic.
• Nation-State Actors: As part of broader network reconnaissance and credential harvesting campaigns.

Attack Campaign Context: No specific campaigns are associated with this CVE. However, SSL stripping attacks are a common component of larger operations targeting enterprise management interfaces.

Geographic Targeting: No geographic patterns are known.

Industry Verticals Most at Risk:

• Government: Using HCL IEM for endpoint management.
• Finance: Managing regulated endpoints.
• Healthcare: Managing medical devices and workstations.
• Technology: Large-scale endpoint management.

Connection to Similar Vulnerabilities: This CVE is part of a broader class of HSTS misconfiguration vulnerabilities (CWE-319) that have affected products like Ivanti Connect Secure (CVE-2024-21887) and various web applications.

Exploitation & Lab Setup

Red Team Section

Lab Setup:

1. Environment: Two VMs on the same virtual network:

   • Attacker: Kali Linux with bettercap and sslstrip installed.
   • Victim: Windows 10 with a browser pointing to HCL IEM.
   • Target: HCL IEM server (any version without HSTS).

2. Prerequisites:

   • HCL IEM server accessible via HTTPS.
   • Attacker VM configured for IP forwarding and ARP spoofing.

Exploitation Walkthrough:

1. Enable IP Forwarding:

   echo 1 > /proc/sys/net/ipv4/ip_forward
   

2. ARP Spoofing (using bettercap):

   bettercap -eval "set arp.spoof.targets 192.168.1.100; arp.spoof on"
   

   (Replace 192.168.1.100 with the victim's IP)

3. SSL Strip (using sslstrip):

   sslstrip -l 8080 -w /tmp/sslstrip.log
   

4. Redirect HTTP Traffic:

   iptables -t nat -A PREROUTING -p tcp --destination-port 80 -j REDIRECT --to-port 8080
   

5. Victim Action: The victim navigates to https://iem-server.example.com. The attacker intercepts the request and downgrades it to HTTP.

6. Expected Output: The attacker sees all HTTP traffic in /tmp/sslstrip.log, including session cookies and credentials.

Post-Exploitation: The attacker can use captured session cookies to access the HCL IEM web interface as the victim, potentially gaining administrative access to manage endpoints.

Blue Team Section

Detection of Active Exploitation:

1. Network Traffic Signatures:

   • HTTP requests to a server that should only be accessed via HTTPS.
   • Multiple ARP replies from the same MAC address (ARP spoofing indicator).
   • Unusual HTTP redirects (e.g., 302 redirecting from HTTPS to HTTP).

2. Endpoint Behavioral Indicators:

   • Browser certificate warnings for the HCL IEM domain.
   • Presence of sslstrip or bettercap processes on suspicious hosts.
   • Unusual outbound connections on port 80 to the HCL IEM server.

3. Log Entries:

   • HCL IEM access logs showing HTTP requests (should only show HTTPS).
   • Firewall logs showing traffic on port 80 to the HCL IEM server.

Indicators of Compromise (IOCs)

No confirmed IOCs available — the following patterns are illustrative of exploitation attempts:

Network IOCs:

• HTTP requests to HCL IEM server (should be HTTPS only)
• ARP cache entries with multiple MAC addresses for the same IP
• DNS responses pointing to unexpected IPs (DNS spoofing)

HTTP Request Patterns:

GET / HTTP/1.1
Host: iem-server.example.com

(Note: This should be HTTPS, not HTTP)

File System Artifacts:

• /tmp/sslstrip.log on attacker systems [EXAMPLE — not a real IOC]
• bettercap configuration files

Process Execution Anomalies:

• sslstrip or bettercap processes on non-administrative systems
• arpspoof or ettercap processes

Log Entries:

• HCL IEM access log: 192.168.1.200 - - [21/Jul/2026:14:36:53 +0000] "GET / HTTP/1.1" 200 1234 (HTTP request to HTTPS-only server)

STIX-like IOC List:

Detection Engineering

YARA Rule

rule CVE-2026-56587_Detection {
    meta:
        description = "Detects exploitation of CVE-2026-56587 in HCL IEM via SSL stripping"
        author = "Valters IT Hub"
        date = "2026-07-21"
        reference = "https://www.valtersit.com/cve/cve-2026-56587"
    strings:
        $http_request = "GET / HTTP/1.1\r\nHost:"
        $http_response = "HTTP/1.1 200 OK\r\n"
        $no_hsts = "Strict-Transport-Security"
    condition:
        $http_request at 0 and $http_response and not $no_hsts
}

Sigma Rule (SIEM)

title: CVE-2026-56587 HCL IEM SSL Stripping Detection
id: 2df8ae22-2461-4e44-9340-7f8db1b33bf7
status: experimental
description: Detects HTTP requests to HCL IEM servers that should only be accessed via HTTPS
author: Valters IT Hub
date: 2026-07-21
references:
    - https://www.valtersit.com/cve/cve-2026-56587
logsource:
    category: webserver
    product: hcl_iem
detection:
    selection:
        cs_method: 'GET'
        cs_uri_stem: '/'
        cs_protocol: 'HTTP/1.1'
    condition: selection
falsepositives:
    - Legitimate administrative activity if HTTP is intentionally enabled
level: high

Suricata IDS Rule

alert tcp any any -> any 80 (msg:"CVE-2026-56587 HCL IEM SSL Stripping Attempt"; flow:to_server; content:"GET / HTTP/1.1"; content:"Host: "; content:"iem"; nocase; sid:1000001; rev:1;)

Elastic (EQL) Query

network where destination.port == 80 and http.request.method == "GET" and http.request.uri == "/" and http.request.headers.host == "iem-*"

Splunk SPL Query

index=web sourcetype=access_combined
| search dest_port=80 uri="/" host="iem-*"
| table _time, src_ip, dest_ip, uri, status

Wazuh Rule

<rule id="100001" level="12">
    <if_sid>31100</if_sid>
    <field name="url">^/</field>
    <field name="protocol">HTTP/1.1</field>
    <field name="dest_port">80</field>
    <description>CVE-2026-56587: HTTP request to HCL IEM server</description>
    <group>cve_2026_56587,</group>
</rule>

Remediation & Mitigation

Immediate Actions (0-24 hours)

1. No Patch Available: Since no official patch exists, implement compensating controls:

   • Enable HSTS manually: Configure the web server to send the Strict-Transport-Security header.
   • For Apache Tomcat: Add the following to web.xml:

     <filter>
         <filter-name>HSTSFilter</filter-name>
         <filter-class>org.apache.catalina.filters.AddDefaultCharsetFilter</filter-class>
     </filter>
     

     (Note: This is a simplified example; use a proper HSTS filter implementation.)
   • For IBM HTTP Server: Add to httpd.conf:

     Header always set Strict-Transport-Security "max-age=31536000; includeSubDomains; preload"
     

2. Network-Level Mitigation:

   • Block port 80 inbound/outbound to the HCL IEM server.
   • Implement ARP spoofing detection (e.g., using arpwatch).
   • Use 802.1X network access control to prevent unauthorized devices.

3. Authentication Hardening:

   • Enable multi-factor authentication (MFA) for HCL IEM access.
   • Use certificate-based authentication instead of passwords.

Short-term (1-7 days)

1. Configuration Hardening:

   • Submit the HCL IEM domain to browser HSTS preload lists.
   • Disable HTTP on the HCL IEM server entirely.
   • Implement HTTP Public Key Pinning (HPKP) if supported.

2. Monitoring Implementation:

   • Deploy the detection rules above.
   • Monitor for HTTP traffic to the HCL IEM server.
   • Enable logging of all HSTS violations.

3. Vulnerability Scanning:

   curl -I https://iem-server.example.com | grep -i "Strict-Transport-Security"
   

   If no output, HSTS is not enabled.

Long-term

1. Architecture Changes:

   • Place HCL IEM behind a reverse proxy (e.g., Nginx, HAProxy) that enforces HSTS.
   • Implement network segmentation to isolate management interfaces.
   • Use VPN for all remote access to HCL IEM.

2. Security Control Improvements:

   • Deploy a Web Application Firewall (WAF) with HSTS enforcement.
   • Implement certificate transparency monitoring.
   • Use client certificates for mutual TLS authentication.

3. Developer Training:

   • Educate developers on OWASP Top 10 (A5: Security Misconfiguration).
   • Include HSTS in security requirements for all web applications.

Validation:

• Run curl -I https://iem-server.example.com and verify the Strict-Transport-Security header is present.
• Attempt to access the server via HTTP and confirm it redirects to HTTPS or is blocked.
• Use sslyze to check HSTS configuration:

  sslyze --hsts iem-server.example.com
  

References & Resources

• NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-56587
• CVE.org: https://www.cve.org/CVERecord?id=CVE-2026-56587
• Vendor advisory: See HCL security page
• OSV: https://osv.dev/vulnerability/CVE-2026-56587
• Related CWE: https://cwe.mitre.org/data/definitions/319.html
• MITRE ATT&CK: https://attack.mitre.org/techniques/T1557/

Report generated by Valters IT Hub Neural Engine v25 | 2026-07-21 | https://www.valtersit.com/cve/cve-2026-56587