Security readout for executives and security teams
Plain-English summary
CVE-2020-3409 is a denial-of-service flaw in Cisco IOS and IOS XE PROFINET handling. An unauthenticated attacker on an adjacent network could cause an affected device to crash and reload, interrupting availability. The bundle does not provide exact affected versions or fixed releases.
Executive priority
Treat this as high priority for environments where Cisco network devices support production, industrial, or safety-sensitive operations. The impact is availability loss, not data theft, but repeated reloads can disrupt business processes and operational continuity.
Technical view
The issue is insufficient processing logic for crafted PROFINET packets in Cisco IOS and IOS XE Software. CVSS 3.0 is 7.4 with adjacent attack vector, low complexity, no privileges, no user interaction, changed scope, and high availability impact only. CWE is CWE-20.
Likely exposure
Exposure is most likely where Cisco IOS or IOS XE devices process PROFINET traffic on networks an attacker can reach from an adjacent segment. Exact affected releases are not listed in the provided bundle, so teams must validate against Cisco’s advisory.
Exploitation context
The source bundle does not indicate active exploitation, and CISA KEV status is false. Public evidence provided here supports only the vendor-described crash-and-reload denial-of-service condition, not confirmed exploitation in the wild.
Researcher notes
This is an adjacent-network availability vulnerability, not a remote internet-scale issue based on the provided CVSS vector. The bundle lacks exploit proof, affected release granularity, and patch details, so validation should remain tied to Cisco’s official advisory.
Mitigation direction
- Check Cisco’s advisory for affected and fixed software releases.
- Prioritize devices on industrial or operational networks using PROFINET.
- Limit adjacent-network access to PROFINET-facing device interfaces.
- Apply vendor-recommended updates or mitigations where applicable.
- Increase monitoring for unexpected device reloads.
Validation and detection
- Inventory Cisco IOS and IOS XE devices in scope.
- Identify devices with PROFINET enabled or reachable.
- Compare software versions and configurations against Cisco’s advisory.
- Review device logs for unexplained crashes or reloads.
- Confirm remediation status after any vendor-guided update.
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-20: 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-2020-3409 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
- 7.4 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:C/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:3.0/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H2.84Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
7.4HighVector: CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- 20200924 Cisco IOS and IOS XE Software PROFINET Denial of Service 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.
Improper Input Validation
Improper Input Validation represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.