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Red Lion 700 Series EUVDEUVD-2026-95812

| CVE-2026-33367 CRITICAL
Missing Authentication for Critical Function (CWE-306)
2026-10-09 icscert GHSA-66jm-5jv9-hhhv
9.3
CVSS 4.0 · Vendor: icscert
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Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

  1. Access
    Reach device SNMP service over network
  2. Delivery
    Send unauthenticated SNMP admin request
  3. Exploit
    Retrieve configuration and credentials
  4. Execution
    Modify accounts or device settings
  5. Persist
    Trigger firmware or bootloader downgrade
  6. Impact
    Persist control of OT device

Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A07:2025 - Authentication Failures
ASVS 5.0
V6 - Authentication Authentication required for critical functions
MITRE ATT&CK

1 technique across 1 tactic: Initial Access

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

Exploitation Conditions

Exploitation requires network reachability to the SNMP service on a Red Lion 700 Series device; the described administrative SNMP operations (configuration retrieval, account/setting modification, and firmware/bootloader upgrade or downgrade) are performed with no authentication per the description (CWE-306). Limiting factors: the SNMP interface must be reachable by the attacker (devices segmented behind OT firewalls or with SNMP disabled/filtered are not exposed), and the input CVSS vector's PR:L contradicts the description's 'without any authentication' - if PR:L is accurate, some credential/privilege would be required, so confirm the exact SNMP access requirement against the vendor advisory before de-prioritizing.

Impact

This is a high-priority issue for affected operational-technology environments. CWE-306 (Missing Authentication) combined with the CVSS 4.0 vector (AV:N/AC:L/UI:N) describes a network-reachable, low-complexity flaw requiring no user interaction, and the description states administrative SNMP actions are possible 'without any authentication.' There is a direct conflict in the input: the provided CVSS 4.0 vector sets PR:L (implying some privilege) while the description and CWE-306 both indicate NO authentication is required (PR:N) - verify with the vendor/CISA advisory, as this materially changes risk (unauthenticated is worse). High technical impact is confirmed (VC:H/VI:H, SC:H/SI:H), covering configuration disclosure, account/setting modification, and firmware/bootloader changes. However, EPSS probability is NOT provided, this CVE is NOT listed in CISA KEV, and NO public proof-of-concept is referenced - so there is no current signal of active or widespread exploitation. Net: treat as a serious, patch-soon vulnerability in exposed Red Lion 700 Series devices (especially any with SNMP reachable from untrusted networks), while recognizing the real-world exploitation signals (EPSS/KEV/POC) are presently absent and the authentication prerequisite is contradictory in the source data.

Exploit ScenarioDerived

An attacker with network reach to a Red Lion 700 Series device's SNMP service sends SNMP requests to read the device configuration and then modify user accounts or device settings, or trigger a firmware/bootloader downgrade. Because the described flaw requires no authentication and low attack complexity (AV:N/AC:L), a single network-positioned actor could fully compromise the device. No public exploit code is referenced in the provided intelligence.

Emergency Immediate action required. Why: CRITICAL + active threat signals, no patch available.
No patch listed yet 0.3% exploitation probability (EPSS)

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AnalysisAIv2 – Oct 09, 2026

Red Lion Controls 700 Series devices expose SNMP functions that can be used to perform administrative operations - retrieving configuration files, modifying user accounts or device settings, and initiating firmware or bootloader upgrades or downgrades - while the vendor's description states these actions require no authentication at all (CWE-306, missing authentication for a critical function). The issue is rated 9.3 in the published CVSS v4.0 score, and the independent assessment scores it as critical (CVSS 3.1 base AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H), reflecting full compromise of confidentiality and integrity and a scope change from the network service to the device itself; availability is not scored as impacted. No CISA KEV listing or public proof-of-concept is present in the supplied intelligence, so the current status is no public exploit identified at time of analysis. One caveat worth resolving early: the published v4.0 vector carries PR:L (some privilege/credential), which contradicts the description's 'without any authentication' - confirm the exact SNMP access requirement against the vendor advisory before de-prioritizing, because if the description is correct the real-world severity is closer to the independent PR:N assessment.

Earlier versions of this analysis (1)
v1 Oct 09, 2026 - 15:08 CVSS 8.1

Red Lion Controls (HMS Networks) 700 Series devices expose administrative SNMP functionality - configuration file retrieval, user account and device setting modification, and firmware or bootloader upgrades and downgrades - to network-reachable parties, per ICS-CERT advisory ICSA-26-281-01 (CWE-306, missing authentication for a critical function). The practical risk is highest where SNMP is reachable from an untrusted or flat segment, and the supplied signal set is internally inconsistent: the published CVSS:3.1 vector indicates PR:L (some authentication), while the advisory description and CWE-306 indicate no authentication is required, and the independent assessment scores the issue as unauthenticated remote compromise (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H). No CISA KEV entry and no public exploit code were provided in the input, so exploitation status is best described as no public exploit identified at time of analysis; no EPSS score was supplied either. Impact is high-integrity/high-availability on OT devices because unauthorized firmware or bootloader changes can render a unit inoperable or place it under attacker control.

RemediationAI

No vendor-released patch identified at time of analysis - the supplied references point to the HMS Networks security pages and CISA ICS advisory ICSA-26-281-01 but do not include a fixed firmware version, so the first action is to consult https://www.hms-networks.com/cybersecurity and the ICS advisory for a patched firmware release and apply it once published. Until a fix is available, apply compensating controls in this order of effectiveness: disable the SNMP service entirely on 700 Series devices where SNMP-based management or monitoring is not required, which fully removes the attack surface but also removes any SNMP telemetry or management integration those devices currently provide; if SNMP must remain enabled, block inbound UDP/161 and UDP/162 (and TCP/161 if the implementation supports SNMP over TCP) at the OT firewall or conduit boundary and permit SNMP only from explicitly allowlisted management station addresses on a dedicated management VLAN, accepting that this breaks management-from-general-IT-networks workflows and requires firewall rule maintenance; and where the SNMP service cannot be disabled or filtered, treat the device as internet- and IT-network-exposed only under strict monitoring, alerting on configuration retrieval, account or settings changes, and firmware or bootloader upgrade/downgrade events so that administrative actions taken through SNMP are visible to operations. Do not assume that enabling SNMPv3 authentication and encryption remediates this issue: CWE-306 describes a missing authentication check on the administrative function itself, so confirm with the vendor whether protocol-level authentication actually closes the bypass. Finally, resolve the PR:L versus PR:N discrepancy noted in the published CVSS v4.0 vector against the vendor advisory - if the vector is accurate, some credential or privilege is a prerequisite and prioritization can be adjusted accordingly, but until that is confirmed, treat the SNMP administrative functions as reachable without authentication. Security teams should also treat the referenced advisory IDs as a tracking anchor for follow-up: once a firmware version is named, validate it against the device's current build before closing the item.

Affected VersionsENISA

700 series 0 <Firmware Versions 3.11.0
700 series 0 <Bootloader Versions 2.0.6.1

Affected Packages

euvd 700_series_0_bootloader_versions no fix
euvd 700_series_0_firmware_versions no fix

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 2 packages in euvd

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

The affected component is the SNMP management interface on Red Lion Controls 700 Series devices (CPE cpe:2.3:a:red_lion_controls:700_series:*:*:*:*:*:*:*:*), now part of the HMS Networks portfolio following its acquisition of Red Lion Controls. The root cause class is CWE-306, Missing Authentication for Critical Function: the SNMP agent path that exposes administrative capabilities does not enforce an authentication step, so the critical functions reachable through it - configuration file retrieval, user account and device setting modification, and firmware or bootloader upgrade/downgrade initiation - can be driven by whoever can reach the service. Note that the CPE uses a wildcard version, meaning the advisory's CPE does not itself constrain a fixed version range, so all shipping 700 Series firmware should be treated as potentially affected until the vendor advisory enumerates fixed builds. Because the weakness is missing authentication rather than weak credentials or a protocol-version weakness, protocol hardening alone (for example, moving to SNMPv3) should not be assumed to remediate the exposure unless the vendor states that it does. The SNMP service is the entire attack surface here: if it is not reachable, the vulnerability is not exploitable over the network, which makes segmentation and service exposure the decisive control in OT deployments.

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Severity by source

Vendor (icscert) PRIMARY 9.3 HIGH
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N
vuln.today AI 10.0 CRITICAL

Description states admin SNMP actions occur without authentication so PR:N; network SNMP gives AV:N/AC:L; gateway compromise affects downstream OT (S:C) and firmware/bootloader changes break availability (A:H).

3.1 AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:N

Primary rating from Vendor (icscert).

CVSS VectorVendor: icscert

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
None
Privileges Required
Low
User Interaction
None
Vulnerable system: Confidentiality
High
Vulnerable system: Integrity
High
Vulnerable system: Availability
None
Subsequent system: Confidentiality
High
Subsequent system: Integrity
High
Subsequent system: Availability
None

Lifecycle Timeline

3
Severity Changed
Oct 09, 2026 - 15:22 NVD
HIGH CRITICAL
CVSS changed
Oct 09, 2026 - 15:22 NVD
8.1 (HIGH) 9.3 (CRITICAL)
CVE Published
Oct 09, 2026 - 14:38 cve.org
HIGH 8.1

DescriptionCVE.org

SNMP can be used to perform administrative actions such as retrieving configuration files, modifying user accounts or device settings, and initiating firmware or bootloader upgrades or downgrades-all without any authentication.

Executive ViewAI

Why It Matters

Red Lion Controls 700 Series industrial devices can be fully taken over through their SNMP service without valid credentials, letting anyone who can reach the device read configuration files, change user accounts and settings, and push or roll back firmware. Because these devices typically sit at the edge of operational technology networks, a compromise could expose network architecture and hand an adversary persistent control over connected industrial equipment. No vendor patch or public exploit has been identified, so near-term risk reduction depends on network isolation rather than patching.

Business Impact: Severe
Compensating Controls

No vendor-released patch identified at time of analysis. Interim mitigations: disable SNMP on the 700 Series devices where it is not required for operations; block UDP 161/162 at network boundaries and on host firewalls; segment affected devices onto an isolated management VLAN with access restricted to allow-listed management hosts; monitor and alert on SNMP write/administrative operations, unauthorized account creation, and unscheduled firmware or bootloader changes; and restrict physical and remote access to the devices until a vendor fix is released.

Threat Intelligence Overview

EPSS Score
0.3%
Top 80% exploitable
Prevalence
Low
niche industrial OT communication/gateway hardware, industry-specific not broadly deployed
Threat Intel
1
1 source
Data Quality
6 sources
Confidence: High
EUVD NVD CVE.org EPSS Vulnrichment CISA GitHub

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity CRITICAL
CISA KEV No
Public POC No
EPSS 0.3%
Patch available No
Active threat Yes
Deciding rule
CRITICAL + active threat signals, no patch available
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision
Scheduled
Exploitation
None
System Exposure· derived
Open
Automatable
No
Human Impact
Very High
Technical Impact
Total

Priority Score

56
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +46
PoC: 0
Weaponized: 0
Threat intel: +10
Gov advisory: 0

Attack Technique

Authentication bypass attacks exploit flaws in the verification mechanisms that control access to systems and applications.

Threat IntelligenceMISP

CISA Advisories
Sources: CISA (public domain)

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