Security readout for executives and security teams
Plain-English summary
This flaw affects Rockwell MicroLogix controllers and RSLogix 500 software. A hard-coded cryptographic key can undermine password protection and may allow a remote attacker to gain unauthorized controller access. For industrial environments, that creates potential operational and safety-impacting risk if affected controllers are reachable.
Executive priority
High priority for OT asset owners. The issue is critical severity and could affect controller access, but public evidence provided here does not confirm active exploitation. Focus on asset identification, exposure reduction, and vendor-directed remediation.
Technical view
CVE-2020-6990 is a CWE-321 hard-coded cryptographic key issue in the RSLogix 500 binary. Affected items include MicroLogix 1400 Series B v21.001 and prior, MicroLogix 1400 Series A all versions, MicroLogix 1100 all versions, and RSLogix 500 v12.001 and prior. CVSS 3.1 is 9.8, network exploitable, no privileges or user interaction required.
Likely exposure
Exposure is likely in OT environments using Rockwell MicroLogix 1100 or 1400 controllers, or RSLogix 500 v12.001 or earlier. Risk is higher where engineering workstations or controllers are reachable from broader enterprise, remote-access, or internet-connected networks.
Exploitation context
The provided sources do not show CISA KEV listing or confirmed active exploitation. The CVE states an attacker could identify cryptographic keys and use them in further cryptographic attacks, potentially leading to remote unauthorized controller access.
Researcher notes
Analysis is limited to the CVE record and CISA ICS advisory reference in the provided bundle. No exploit status, patch version, or detailed mitigation text was included in the bundle, so remediation should be confirmed against vendor and CISA guidance.
Mitigation direction
- Inventory MicroLogix 1100, MicroLogix 1400, and RSLogix 500 deployments.
- Check Rockwell and CISA advisory ICSA-20-070-06 for official remediation guidance.
- Prioritize reducing remote network reachability to affected controllers.
- Restrict engineering workstation access to trusted administrators only.
- Monitor OT networks for unauthorized controller access attempts.
Validation and detection
- Confirm whether RSLogix 500 v12.001 or prior is installed.
- Identify MicroLogix 1400 Series B controllers at v21.001 or prior.
- Treat all MicroLogix 1400 Series A devices as affected.
- Treat all MicroLogix 1100 controllers as affected.
- Review network paths that allow remote access to controllers or engineering workstations.
Public sources used
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-321: 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 lookupCredential and access behavior lookup
The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2020-6990 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
- Critical
- CVSS
- 9.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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.
SSVC decision data
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:H/I:H/A:H3.95.9CISA-ADPVulnerability scoring details
Base CVSS 3.1 score
9.8CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://www.us-cert.gov/ics/advisories/icsa-20-070-06CVE reference, icscert · x_refsource_MISC
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.