Security readout for executives and security teams
Plain-English summary
A network attacker could send a specially crafted EtherNet/IP packet to vulnerable OpENer deployments and crash or stop service availability. The known impact is denial of service, not data theft or code execution, but interruption in industrial communications can affect operations.
Executive priority
Treat this as a high-priority availability risk for environments that rely on OpENer for industrial communications. Prioritize asset identification first because affected downstream products are not named in the provided evidence.
Technical view
CVE-2021-27498 is a reachable assertion issue, CWE-617, in EIPStackGroup OpENer EtherNet/IP commits and versions before February 10, 2021. CVSS 3.1 is 7.5 with network access, low complexity, no privileges, no user interaction, and high availability impact.
Likely exposure
Exposure is most likely where OpENer EtherNet/IP is embedded in industrial, lab, or automation systems and reachable over a network. The sources do not identify specific downstream vendors or packaged products.
Exploitation context
The provided sources describe a specifically crafted packet causing denial of service. CISA KEV status is false in the bundle, so there is no source-backed evidence here of active exploitation.
Researcher notes
The public evidence is narrow: affected product, date boundary, CWE, CVSS, and denial-of-service impact. Do not assume code execution, confidentiality impact, or active exploitation without additional sourced evidence.
Mitigation direction
- Inventory systems using EIPStackGroup OpENer EtherNet/IP.
- Identify builds or commits older than February 10, 2021.
- Check the CISA advisory and OpENer repository for vendor remediation guidance.
- Limit network reachability to trusted industrial management paths until remediated.
- Monitor vulnerable services for crashes or unexpected restarts.
Validation and detection
- Confirm whether OpENer EtherNet/IP is present in deployed systems.
- Record the exact OpENer commit or build date.
- Compare versions against the before-February-10-2021 affected range.
- Review CISA advisory ICSA-21-105-02 for any environment-specific guidance.
- Validate remediation in a controlled test environment before production rollout.
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-617: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-27498 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://www.cisa.gov/uscert/ics/advisories/icsa-21-105-02CVE reference · x_refsource_CONFIRM
- https://github.com/EIPStackGroup/OpENerCVE reference · x_refsource_CONFIRM
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Reachable Assertion
Reachable Assertion represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.