CVE-2023-22583

Executive Summary

CVE-2023-22583 is a critical SQL injection vulnerability in the login forms of the Danfoss AK-EM100 energy management device. With a CVSS score of 10.0, the flaw allows an unauthenticated remote attacker to inject arbitrary SQL commands through web form input fields, likely enabling authentication bypass and full database compromise. The AK-EM100 is declared End-of-Life (EOL); Danfoss has not released a firmware patch, and the only vendor-provided mitigation is device replacement. All deployed AK-EM100 units remain exposed unless isolated or decommissioned.

Technical Analysis

The NVD description specifies that "the Danfoss AK-EM100 web forms allow for SQL injection in the login forms." This indicates that user-supplied input in the login authentication forms is concatenated into SQL queries without sufficient sanitization or parameterization. The attack surface is the embedded web server exposing the login page over HTTP/HTTPS on the device’s network interface.

Vulnerability mechanism: An attacker submits crafted input (e.g., SQL metacharacters like ' or --) into the username and/or password fields. If the application does not use prepared statements, the injected payload alters the SQL query’s logic — a classic ' OR '1'='1 pattern can bypass authentication entirely, granting access to the web administration interface without valid credentials.

Attack surface specifics: The input vectors are web form fields in the login page. No additional endpoints, parameter names, or code-level details are provided in the CVE data. The CVSS vector (inferred from the 10.0 score) reflects network accessibility, no privileges required, no user interaction, and high confidentiality/integrity/availability impact with a possible scope change. The lack of a CWE assignment in the provided data is unusual; however, the mechanism aligns with CWE-89 (SQL Injection).

Device context: The AK-EM100 is an energy management controller used in commercial/industrial refrigeration and HVAC systems. It operates as a building automation component, typically connected to both the corporate network and operational technology (OT) networks. The absence of a patch — compounded by EOL status — means the vulnerability remains permanently exploitable on any reachable device.

Exploitation Scenarios

Because no public PoC or exploit code is confirmed, the following attack chain is inferred strictly from the vulnerability class and the NVD description.

1. Reconnaissance / target identification: An attacker scans for internet-facing AK-EM100 devices using Shodan/Censys queries targeting the vendor’s web interface (e.g., HTTP title or banner containing "AK-EM100"). Alternatively, in a lateral movement scenario, the attacker identifies the device via internal network scans on common HTTP ports (80, 443, 8080).

2. Triggering the flaw: The attacker navigates to the login page served by the AK-EM100 web forms. In the username or password input fields, they submit a specially crafted SQL injection payload. Because the description confirms SQL injection exists in the login forms, no prior authentication is required.

3. Payload / execution method (vulnerability-class level): A generic authentication-bypass payload — for example, submitting ' OR '1'='1' -- as the username with a dummy password — causes the backend SQL query to return a valid row, bypassing credential checks. More advanced payloads could use stacked queries (if supported) to execute INSERT, UPDATE, or DELETE statements, or invoke database functions to read files or write web shells if the database service has elevated privileges.

4. Post-exploitation impact: Successful authentication bypass grants full administrative access to the device’s web management interface. An attacker can then:

   • Modify energy management setpoints, potentially causing equipment damage or disrupting cooling/heating operations.
   • Exfiltrate sensitive operational data (e.g., energy consumption logs, configuration parameters).
   • Use the device as a pivot point to reach other OT/ICS assets on the same network segment.
   • Leverage the device’s network position to launch further attacks, given its trusted placement in industrial control networks.

No public evidence exists of in-the-wild exploitation; the EPSS score of 0.00755 indicates low immediate exploitation likelihood, but the severity score and the EOL status demand proactive risk mitigation.

Impact Assessment

The CVSS base score of 10.0 reflects the most severe impact profile: network-exploitable, no authentication, no user interaction, and high impact across confidentiality, integrity, and availability. The scope is likely changed, meaning the compromise can extend beyond the vulnerable component to affect adjacent systems.

• Confidentiality: Attackers can read databases containing configuration data, energy telemetry, and potentially credentials used for other network services.
• Integrity: Full admin access enables modification of device settings, which can corrupt operational processes (e.g., altering temperature setpoints in refrigeration units, causing food spoilage or HVAC failure).
• Availability: An attacker could issue commands that crash the device’s web service or the embedded controller itself, disrupting building automation functions that depend on the AK-EM100.
• Blast radius: In OT environments, this device is a network pivot point. Compromise could lead to lateral movement toward PLCs, SCADA servers, or other ICS components on the same network segment.

Affected systems: All Danfoss AK-EM100 units still in service — no patched firmware is available. The EOL designation means even current deployments are unsupported.

Detection Guidance

Sigma Rule

title: Danfoss AK-EM100 SQL Injection Attempt - Login Form
id: 5f61b2e7-3a14-4c1f-9b8a-2f49d3a1c8e4
status: experimental
description: Detects SQL injection patterns in HTTP requests to Danfoss AK-EM100 login pages
logsource:
  category: webserver
  product: generic
detection:
  selection:
    http.url_path|contains: 
      - '/login'
      - '/auth'
    http.request_body|contains:
      - "' OR '1'='1"
      - "' OR '1'='1' --"
      - "UNION SELECT"
      - "'; DROP TABLE"
      - "sleep(10)"
      - "WAITFOR DELAY"
  condition: selection
fields:
  - src_ip
  - http.user_agent
  - http.request_body
falsepositives:
  - Legitimate security scanning tools
  - Malformed input from automation scripts
level: high

YARA Rule

rule Danfoss_AKEM100_SQLi_NetworkPatterns
{
    meta:
        author = "valtersit.com Threat Intel"
        description = "Detects SQL injection payload patterns targeting Danfoss AK-EM100 web login"
        cve = "CVE-2023-22583"
        date = "2024-05-15"
    strings:
        $s1 = "' OR 1=1" ascii nocase
        $s2 = "' OR '1'='1" ascii nocase
        $s3 = "UNION SELECT" ascii nocase
        $s4 = "admin'--" ascii nocase
        $s5 = "'; DROP TABLE" ascii nocase
        $s6 = "WAITFOR DELAY" ascii nocase
        $s7 = "AK-EM100" ascii nocase
    condition:
        any of ($s1, $s2, $s3, $s4, $s5, $s6) and $s7
}

Suricata IDS Rule

alert http any any -> $HOME_NET any (msg:"CVE-2023-22583 Danfoss AK-EM100 SQL Injection Attempt"; flow:to_server,established; http.uri; content:"login"; http.uri; nocase; content:"AK-EM"; http.header; nocase; content:"' OR '1'='1"; http.client_body; nocase; content:"UNION SELECT"; http.client_body; nocase; sid:202322583; rev:1; reference:cve,2023-22583;)

Elastic Detection

sequence by source.ip, destination.ip with maxspan=1m
  [ network where destination.port in (80, 443, 8080) and
    network.protocol == "http" and
    url.path like~ "*login*" and
    (url.query like~ "*' OR '1'='1*" or 
     request.body like~ "*' OR 1=1*" or 
     request.body like~ "*UNION SELECT*" or 
     request.body like~ "*WAITFOR DELAY*") ]
  [ http where process.name == "httpd" and
    response.status_code == 200 and
    response.body like~ "*AK-EM100*" ]

Splunk SPL Query

index=web sourcetype=access_combined
| where match(_raw, "(?i)AK-EM100") AND match(_raw, "(?i)('%20OR%20'1'='1|UNION SELECT|WAITFOR DELAY|' OR 1=1)")
| table _time, src_ip, dest_ip, uri_path, http_user_agent
| sort - _time

Wazuh OSSEC Rule

<rule id="100223" level="15">
  <decoded>
    <program_name>apache</program_name>
  </decoded>
  <match>AK-EM100</match>
  <regex>(' OR '1'='1|UNION SELECT|WAITFOR DELAY|' OR 1=1)</regex>
  <description>Possible SQL injection attempt against Danfoss AK-EM100 login</description>
  <group>web_attack,sql_injection,</group>
  <mitre>
    <id>T1190</id>
  </mitre>
</rule>

Mitigation & Patch Guidance

Patch confidence: 1/4 — PARTIAL. There is no official firmware fix. Danfoss has declared the AK-EM100 End-of-Life and instructs customers to phase out the device.

1. Immediate mitigations (apply today):

   • Restrict network access: Use firewall rules to block all external access to the AK-EM100’s web interface (ports 80/443/8080). Only allow access from trusted management subnets via VPN.
   • If the device must remain accessible, place it behind an application-level proxy that filters SQL metacharacters and known injection patterns.
   • Change default credentials and enforce strong, unique passwords for any local accounts (reduces — but does not eliminate — risk).
   • Monitor network traffic to the device for anomalous login attempts and SQL injection payload patterns.

2. Patch/upgrade steps:

   • Contact Danfoss support to confirm there is no firmware update; the EOL status means none is expected.
   • Replace the AK-EM100 with a currently supported successor device (e.g., Danfoss AK-EM200 or newer energy management controller) that receives security updates.
   • During migration, isolate the AK-EM100 on a separate OT VLAN and restrict egress/inbound traffic to only required protocols.

3. Long-term hardening:

   • Inventory all OT/ICS devices and flag EOL hardware for prioritised replacement in capital planning.
   • Enforce network segmentation between IT and OT per IEC 62443 standards; place devices like AK-EM100 in a demilitarized zone with strict access control lists.
   • Implement continuous monitoring of OT network traffic with ICS-aware IDS/IPS solutions (e.g., Suricata with DNP3/Modbus rules) to detect scanning or exploitation attempts.
   • Maintain a risk register for unpatched known-vulnerable devices; review quarterly, escalate to management if replacement is delayed beyond 6 months.

References

1. NVD Entry — https://nvd.nist.gov/vuln/detail/CVE-2023-22583
2. Danfoss Product Page (AK-EM100 EOL notice) — https://www.danfoss.com/en/products/electronic-controls/ak-em100/
3. CISA Known Exploited Vulnerabilities Catalog — not listed (https://www.cisa.gov/known-exploited-vulnerabilities-catalog)
4. MITRE ATT&CK Technique T1190 — https://attack.mitre.org/techniques/T1190/
5. EPSS (Exploit Prediction Scoring System) data — https://www.first.org/epss/

Threat actor campaigns: No known threat actor campaigns or exploit-in-the-wild evidence have been publicly reported as of this writing. The EPSS score of 0.00755 (51.7th percentile) indicates a moderate likelihood of eventual exploitation, especially given the trivial attack chain and high severity score.