Security readout for executives and security teams
Plain-English summary
CVE-2020-3217 is a high-severity Cisco network device flaw. An attacker on the same network segment could send a malicious Cisco Discovery Protocol message, potentially taking over the device with administrative privileges or forcing a reload that disrupts service.
Executive priority
Treat as high priority for network infrastructure. The attacker must be adjacent, but successful exploitation could grant administrative control or interrupt core connectivity. Focus first on critical devices with untrusted or broad Layer 2 exposure.
Technical view
The flaw is in Cisco onePK Topology Discovery Service parsing of Cisco Discovery Protocol messages. Insufficient length restrictions can trigger a stack overflow, enabling arbitrary code execution with administrative privileges or a process crash causing device reload and denial of service.
Likely exposure
Exposure is most likely on Cisco IOS, IOS XE, IOS XR, or NX-OS devices running affected onePK Topology Discovery Service code and reachable by adjacent Cisco Discovery Protocol traffic. Exact affected releases are not provided in the bundle and should be checked against Cisco guidance.
Exploitation context
The source bundle describes unauthenticated adjacent-network exploitation with low attack complexity and no user interaction. It does not cite active exploitation, and KEV status is false, so active exploitation should not be claimed from these sources.
Researcher notes
Key evidence is Cisco’s description of CDP parsing with insufficient length restrictions leading to stack overflow. The bundle lacks affected version detail, fixed release names, workaround text, and proof of exploitation in the wild.
Mitigation direction
- Review Cisco’s advisory for affected releases and vendor-supported fixed software.
- Prioritize remediation for reachable production routing and switching infrastructure.
- Limit untrusted Layer 2 adjacency to Cisco devices where operationally feasible.
- Monitor for unexpected device reloads or crashes on affected platforms.
Validation and detection
- Inventory Cisco IOS, IOS XE, IOS XR, and NX-OS devices in scope.
- Check whether onePK Topology Discovery Service exposure applies to each device.
- Compare device software releases against Cisco’s advisory.
- Review logs for crashes, reloads, or suspicious adjacent discovery traffic.
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 lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2020-3217 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
- 8.8 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:A/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.
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:U/C:H/I:H/A:H2.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
8.8HighVector: CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- 20200603 Cisco IOS, IOS XE, IOS XR, and NX-OS Software One Platform Kit Remote Code Execution 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.