Security readout for executives and security teams
Plain-English summary
This flaw affects Cisco industrial router software used in operational environments. A remote unauthenticated attacker could send crafted VLPWA modem messages and either read sensitive data or cause the VLPWA interface to shut down. Business urgency is high where affected industrial routers are reachable from untrusted networks.
Executive priority
Treat this as high priority for industrial sites using the affected Cisco router families, especially where network segmentation is weak. The main business concern is unauthorized sensitive data access or disruption to LPWA-related communications, not confirmed active exploitation.
Technical view
CVE-2020-3426 is an input validation weakness in Cisco IOS Low Power, Wide Area VLPWA handling. The supplied CVSS 3.1 score is 7.5, with network attack vector, low complexity, no privileges, and no user interaction. The described impact is high confidentiality loss or VLPWA interface denial of service.
Likely exposure
Exposure is most likely in organizations operating Cisco 800 Series Industrial ISRs or Cisco 1000 Series CGR1000 routers with affected Cisco IOS software, specifically the supplied affected entry Cisco IOS 15.2(6)E4. Internet or broad network reachability would increase risk.
Exploitation context
The source bundle does not show CISA KEV listing or cited evidence of active exploitation. The vulnerability is still practical in principle because the described attack is remote, unauthenticated, low-complexity, and uses crafted packets sent to an affected device.
Researcher notes
The evidence provided identifies missing input and validation checks for VLPWA protocol modem messages. The source bundle does not include exploit code, confirmed exploitation, or detailed Cisco fixed-release data. Avoid broad product assumptions beyond the listed Cisco industrial router families and supplied IOS entry.
Mitigation direction
- Use the Cisco advisory as the source of truth for fixed software or workarounds.
- Inventory Cisco 800 Industrial ISR and CGR1000 devices and record IOS versions.
- Prioritize remediation for affected routers reachable from untrusted or shared networks.
- Restrict untrusted network paths to VLPWA-capable industrial routers where operationally feasible.
- Monitor affected devices for unexpected VLPWA interface shutdowns or confidentiality-related anomalies.
Validation and detection
- Confirm whether deployed devices match Cisco 800 Industrial ISR or CGR1000 families.
- Verify installed Cisco IOS versions against the Cisco advisory and affected release data.
- Determine whether VLPWA functionality is enabled or reachable in the device environment.
- Check whether exposed devices can receive traffic from untrusted network segments.
- Review operational telemetry for unexpected VLPWA interface shutdowns or related faults.
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
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ATT&CK lookup starting points
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CWE-264: Exact CWE lookup
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Open ATT&CK lookupCVE-2020-3426 mapping review
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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:H/I:N/A:N
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:H/I:N/A:N3.93.6Primary 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:H/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- 20200924 Cisco IOS Software for Cisco Industrial Routers Virtual-LPWA Unauthorized Access VulnerabilityCVE reference · vendor-advisory, x_refsource_CISCO
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.
Permissions, Privileges, and Access Controls
Permissions, Privileges, and Access Controls represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.