CVE-2021-33022

Executive Summary

CVE-2021-33022 is a cleartext transmission vulnerability affecting Philips Vue PACS (Picture Archiving and Communication System) versions 12.2.x.x and prior. The vulnerability allows unauthorized actors to sniff sensitive or security-critical data transmitted over the network in unencrypted form, exposing medical imaging data and associated patient information. With a CVSS score of 7.5 (High), this flaw impacts healthcare organizations relying on Philips Vue PACS for diagnostic imaging workflows, potentially leading to confidentiality breaches of protected health information (PHI) and other sensitive medical data.

Technical Analysis

Philips Vue PACS is a medical imaging platform used in radiology departments and healthcare enterprise environments for the acquisition, storage, retrieval, and distribution of medical images (e.g., X-ray, CT, MRI) and associated patient metadata. The system typically operates in a distributed architecture where multiple client workstations, image acquisition modalities, and server components communicate over the hospital network.

The vulnerability described in CVE-2021-33022 is a cleartext transmission of sensitive information (CWE-319). This class of vulnerability occurs when an application transmits data — such as authentication credentials, session tokens, patient health information, or diagnostic image data — over a network channel without adequate encryption (e.g., TLS/SSL, IPsec). Any actor with the ability to observe network traffic (e.g., via ARP spoofing, port mirroring, passive sniffing on the same LAN segment, or compromised network infrastructure) can intercept and read the transmitted data in plaintext.

The exact technical implementation details — including which specific communication channels, protocols, or data elements are affected — are not fully disclosed in the available CVE description. The NVD description indicates only that "Philips Vue PACS versions 12.2.x.x and prior transmits sensitive or security-critical data in cleartext in a communication channel that can be sniffed by unauthorized actors."

Insufficient technical detail is available to identify specific endpoints, port numbers, or protocol identifiers impacted. However, based on the vulnerability class, the attack surface includes:

1. Client-server communications: Vue PACS clients communicating with central archive servers.
2. Inter-service communications: Middleware, integration engines, and application server interactions.
3. Modality-to-PACS communications: Medical imaging modalities (e.g., CT, MRI scanners) transmitting DICOM (Digital Imaging and Communications in Medicine) data to the PACS archive.

Given the nature of PACS environments, DICOM protocol transmissions are particularly relevant. DICOM by default does not mandate encryption, and many PACS deployments historically transmit imaging data and patient identifiers (name, DOB, MRN) in the clear over internal networks. While the CVE description does not explicitly confirm DICOM involvement, it aligns with the general exposure profile of Vue PACS deployments.

The CVSS vector for this issue (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N) indicates the following characteristics:

• Attack Vector: Network — the vulnerability is exploitable remotely over a network path.
• Attack Complexity: Low — no unusual conditions are required for a successful attack.
• Privileges Required: None — no authentication or authorization is needed to exploit the flaw (i.e., to sniff the traffic).
• User Interaction: None — no user action is required for exploitation.
• Confidentiality Impact: High — complete or substantial disclosure of sensitive data is possible.
• Integrity/Availability Impact: None — the flaw does not directly enable data modification or denial of service.

The EPSS score is 0.00634 (47.2% percentile), indicating that the probability of active exploitation in the wild is relatively low. No CISA KEV inclusion has been made, and no public PoC or exploit code is known to exist at the time of this writing.

Exploitation Scenarios

No public PoC or exploit code is available for CVE-2021-33022. The attack chain below is inferred from the vulnerability class (cleartext transmission) and standard network attack methodologies.

Step 1 — Reconnaissance / Target Identification An attacker first identifies a target network running Philips Vue PACS. This could be done through network scanning (e.g., Shodan) for exposed PACS ports (e.g., DICOM port 104, HTTPS management interfaces, proprietary ports), or through lateral movement within an already-compromised healthcare network. The attacker seeks to position themselves on the same network segment (LAN, VLAN, or routed segment with traffic visibility) where Vue PACS components communicate.

Step 2 — Triggering the Flaw / Enabling Sniffing No active exploitation of an application flaw is required — the vulnerability is passive in nature. The attacker enables promiscuous mode on their network interface or uses a network tap, port mirror, or ARP spoofing to receive traffic destined to or originating from Vue PACS servers and clients. Because data is transmitted in cleartext, the attacker does not need to bypass encryption — the security-critical information is already visible on the wire.

Step 3 — Payload / Execution Method There is no payload in the traditional sense. The "execution" is the interception and parsing of network packets. At the vulnerability-class level, the attack involves using a packet-capture tool (e.g., Wireshark, tcpdump) or a custom packet-parsing script to collect traffic from protocols such as DICOM (which embeds patient identifiers and may include image data), SQL database traffic, or application-layer REST/SOAP communications that carry sensitive payloads.

Step 4 — Post-Exploitation Impact Once the attacker has captured sufficient traffic, they can extract and reconstruct sensitive information, including:

• Patient protected health information (PHI) — names, dates of birth, medical record numbers.
• Medical imaging data and radiology reports.
• Authentication credentials (usernames/passwords) if transmitted in clear text, enabling further lateral movement or unauthorized access to the PACS system.
• Workflow metadata that aids in planning further attacks (e.g., attacker learns system architecture, server roles, IP addresses).

The confidentiality breach has direct HIPAA/GDPR compliance implications and can lead to identity theft, insurance fraud, or targeted social engineering if PHI is exfiltrated.

Impact Assessment

Cleartext transmission of sensitive data in a healthcare PACS environment carries significant business and regulatory risk.

Business Impact:

• Regulatory and Legal Exposure: Breach of PHI triggers mandatory notification requirements under HIPAA (US), GDPR (EU), and other data protection regulations. Fines can range from tens of thousands to millions of dollars depending on scope and severity.
• Reputational Damage: Healthcare institutions suffer significant trust erosion when patient data is compromised. Public disclosure of a PHI breach can damage a hospital or health system's brand.
• Operational Disruption: Forensic investigations, remediation, and potential system shutdowns to address the vulnerability could impact radiology operations and patient care workflows.
• Financial Cost: Breach notification costs, legal fees, credit monitoring for affected patients, and potential class-action lawsuits.

Affected Systems and Blast Radius:

• All Philips Vue PACS deployments running versions 12.2.x.x and prior.
• The blast radius includes any network segment where Vue PACS traffic traverses in cleartext — this typically includes clinical networks, enterprise LANs, and potentially remote workstations if traffic is routed over unencrypted VPN tunnels.
• Given that the vulnerability requires network proximity or access to the internal network, the most likely exploitation vector is an insider threat (e.g., a disgruntled employee with LAN access), a compromised endpoint on the same network segment, or an attacker who has already achieved a foothold in the network.

CVSS Implications:

• The CVSS score of 7.5 reflects a high severity due to the low attack complexity, no privileges required, and high confidentiality impact. However, the absence of integrity or availability impact, and the passive nature of the attack, moderate the real-world risk compared to actively exploitable remote code execution vulnerabilities.

EPSS Assessment:

• With an EPSS score of 0.00634 and no known public exploit, the immediate threat of mass exploitation is low. However, in a targeted attack scenario (e.g., a malicious actor specifically targeting a healthcare institution), the vulnerability is trivially exploitable and requires minimal technical skill once network access is achieved.

Detection Guidance

Sigma Rule

title: Potential Cleartext Data Transmission Associated with Philips Vue PACS
id: 4f6e2a3b-8c5d-4e9f-b77a-2d1c48f9e653
status: experimental
description: Detects network connections to/from known Philips Vue PACS ports without TLS/SSL negotiation, which may indicate cleartext transmission of sensitive medical data.
author: Valtersit Threat Intelligence
date: 2024/01/15
logsource:
  category: network_connection
  product: windows
detection:
  selection_pacs_ip:
    destination.ip:
      - '10.0.0.0/8'
      - '172.16.0.0/12'
      - '192.168.0.0/16'
    destination.port:
      - 104
      - 11112
      - 2575
      - 8080
  selection_no_tls:
    network.protocol: 'TCP'
    tls.version: null
  condition: selection_pacs_ip and selection_no_tls
  timeframe: 15m
falsepositives:
  - Non-PACS devices using same ports
  - Legacy PACS configurations that use plaintext by design
level: medium
tags:
  - attack.discovery
  - attack.t1040

YARA Rule

rule Philips_Vue_PACS_Cleartext_Traffic
{
    meta:
        author = "Valtersit Threat Intelligence"
        description = "Detect cleartext network payloads containing patient data or DICOM headers common to Philips Vue PACS traffic"
        date = "2024-01-15"
        severity = "medium"
        reference = "CVE-2021-33022"

    strings:
        $dicom_header = "DICM" ascii
        $patient = "PatientName" ascii nocase
        $study = "StudyDescription" ascii nocase
        $pacs_id = "VuePACS" ascii nocase
        $philips = "Philips" ascii nocase
        $mrn = "PatientID" ascii nocase

    condition:
        ($dicom_header and $patient) or ($dicom_header and $study) or
        ($pacs_id and ($patient or $study or $mrn)) or
        ($philips and $patient and ($study or $mrn))
}

Suricata IDS Rule

alert tcp any any -> any 104,11112,2575,8080 (msg:"CVE-2021-33022 - Potential Philips Vue PACS Cleartext Data Exfiltration"; flow:established,to_server; content:"DICM"; offset:128; depth:4; content:"PatientName"; nocase; distance:0; within:100; classtype:attempted-recon; sid:2021330221; rev:1; reference:cve,2021-33022;)

Elastic Detection

sequence by host.name with maxspan=5m
  [ network where
      network.protocol == "tcp" and
      destination.port in (104, 11112, 2575, 8080) and
      not network.transport.tls ]
  [ process where event.type == "start" and
      process.name in ("tcpdump", "wireshark", "dumpcap", "tshark") ]

Splunk SPL Query

sourcetype=network_connections OR sourcetype=firewall_traffic
| where match(dest_port, "^(104|11112|2575|8080)$") 
| where isnull(tls_version) 
| search dest_ip IN (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16)
| stats count min(_time) as first_seen max(_time) as last_seen by src_ip, dest_ip, dest_port
| where count > 50
| sort - count
| rename src_ip as "Source IP", dest_ip as "Destination IP", dest_port as "Destination Port"

Wazuh OSSEC Rule

<group name="philips_pacs,">
  <rule id="330221" level="10">
    <if_sid>100001</if_sid>
    <field name="destinationPort">^104$|^11112$|^2575$|^8080$</field>
    <field name="protocol">TCP</field>
    <description>Potential cleartext transmission of sensitive data to Philips Vue PACS ports - CVE-2021-33022</description>
    <group>pacs_cleartext,</group>
  </rule>
  <rule id="330222" level="12">
    <if_sid>330221</if_sid>
    <field name="destinationAddress">^10\.|^172\.(1[6-9]|2[0-9]|3[01])\.|^192\.168\.</field>
    <description>Confirmed internal network connection to PACS ports with no TLS - CVE-2021-33022</description>
    <group>pacs_cleartext,</group>
  </rule>
</group>

Mitigation & Patch Guidance

Patch confidence is rated 2/4 (CLAIMED) — a single source (the CNA) claims a patch exists, but it has not been independently confirmed.

Immediate Mitigations (short-term, until patched):

1. Segment the network: Isolate Vue PACS components on dedicated VLANs with strict firewall rules limiting traffic to the minimum set of required hosts and ports. Do not allow PACS traffic to traverse general-purpose network segments where unauthorized endpoints exist.
2. Enable network encryption: Where possible, configure TLS/SSL or IPsec for all inter-component communications. For DICOM traffic, consider DICOM TLS (DICOM Part 15) if supported by the deployment.
3. Monitor network traffic: Implement the detection rules above (Suricata, Wazuh, Splunk, etc.) to identify cleartext PACS traffic and alert on any anomalous network activity.
4. Restrict physical/logical access: Implement 802.1X port authentication or MAC address filtering on network switches where feasible. Limit administrative access to network infrastructure.
5. Disable unnecessary services: Review the Vue PACS environment against the Philips D000763414 Vue_PACS_12_Ports_Protocols_Services_Guide and disable any ports or services not required for operation.

Patch/Upgrade Steps:

1. Contact Philips support or your Philips sales representative to verify eligibility for the patched release (Version 12.2.8.0, released May 2021, which addresses the vulnerability for the Speech component).
2. Apply the relevant patches in a test/staging environment first, following Philips' standard upgrade and change-management procedures.
3. Validate the patched environment — confirm that no cleartext transmission paths remain using packet capture analysis.
4. Note: The advisory indicates not all releases may be available in all jurisdictions due to country-specific regulations. Contact Philips directly for deployment-specific guidance.

Long-Term Hardening:

1. Encryption-in-transit policy: Mandate TLS 1.2+ (or stronger) for all sensitive communications within the healthcare network. Implement a policy that all PACS-related protocols, including DICOM, use encrypted channels.
2. Network architecture: Move to a zero-trust model where network segments are isolated and all traffic is authenticated and encrypted regardless of network zone.
3. Continuous monitoring: Deploy network-based intrusion detection and anomaly detection tools specifically tuned to detect plaintext medical data on the wire.
4. Vendor security review: Engage Philips periodically to review security configurations and ensure that the deployed environment aligns with their latest security guidance.
5. Asset inventory: Maintain an up-to-date inventory of all Philips Vue PACS instances and their version numbers to ensure timely patch application in the future.
6. Training: Educate IT staff and network administrators on the risks of cleartext medical data and the importance of network segmentation in clinical environments.

References

1. NVD Entry: https://nvd.nist.gov/vuln/detail/CVE-2021-33022
2. Philips Product Security Advisory: https://www.philips.com/a-w/security/security-advisories.html
3. Philips eService Portal: https://www.philips.com/healthcare/sites/eService (for patch availability and quote requests)
4. DICOM Standard (Part 15 — Security): https://www.dicomstandard.org/current
5. CISA Known Exploited Vulnerabilities Catalog: Not listed for this CVE (as of publication date).

Threat Actor Activity / Exploit-in-the-Wild Evidence: As of the publication date, no known threat actor campaigns specifically leveraging CVE-2021-33022 have been documented. There is no evidence of active exploitation in the wild. The absence of public PoC code and the passive nature of the exploit — combined with the requirement for network positioning — likely limits the attractiveness of this vulnerability for mass exploitation. However, healthcare infrastructure remains a high-value target for financially motivated attackers (ransomware gangs) and nation-state actors, and network sniffing of medical data has historically been observed in sophisticated intrusions. The vulnerability should be treated as a material risk in healthcare environments and remediated accordingly.