Security readout for executives and security teams
Plain-English summary
This CVE affects the Telnet service in Contiki 3.0. A remote attacker may be able to crash an affected device when directory listing behavior encounters many long filenames. The documented impact is denial of service, not data theft or code execution.
Executive priority
Prioritize environments where embedded devices expose Telnet beyond a trusted management segment. If Telnet is disabled or isolated, urgency is lower, but asset owners should still confirm vendor remediation guidance.
Technical view
The source description reports a buffer overflow in Contiki 3.0 Telnet handling. The ls command is mishandled when a directory contains many files with long names, allowing a remote denial of service. The bundle provides no CVSS score, CWE, confirmed patch, or detailed affected CPEs.
Likely exposure
Exposure is most likely in embedded or IoT firmware that uses Contiki 3.0 and has Telnet enabled, especially if reachable from untrusted networks. The source bundle does not identify specific downstream products.
Exploitation context
The CVE is not listed as KEV in the bundle, and no provided source states active exploitation. Practical risk depends on whether Telnet is remotely reachable and whether affected Contiki 3.0 code is present.
Researcher notes
Evidence is limited to the CVE description and referenced Contiki issue. The record names Contiki 3.0 and denial of service, but lacks CVSS, CWE, affected CPEs, patch status, and exploitation evidence.
Mitigation direction
- Inventory firmware and services for Contiki 3.0 Telnet usage.
- Disable Telnet where it is not operationally required.
- Restrict Telnet access to trusted management networks only.
- Check Contiki project or vendor guidance for an approved fix.
- Monitor affected devices for unexpected crashes or service resets.
Validation and detection
- Confirm whether products or firmware include Contiki 3.0.
- Verify whether the Telnet service is enabled and reachable.
- Review directories exposed to Telnet workflows for many long filenames.
- Check operational logs for Telnet-linked crashes or resets.
- Validate mitigations through configuration review, not exploit reproduction.
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.
CVE-2021-38386 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
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
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 and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/contiki-os/contiki/issues/2687CVE reference · 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.