Security readout for executives and security teams
Plain-English summary
CVE-2021-46901 is a stack-based buffer overflow in CETIC-6LBR 1.5.0. A long URL sent to the built-in webserver over a 6LoWPAN network can overflow memory. The public sources do not provide a severity score, confirmed exploitation, or a named fixed version.
Executive priority
Treat this as a targeted IoT exposure issue rather than a broad enterprise emergency. Prioritize environments using 6LBR in operational or sensor networks, especially where untrusted devices can reach the webserver.
Technical view
The issue is reported in examples/6lbr/apps/6lbr-webserver/httpd.c, where strcat use can overflow a stack buffer when handling an overly long URL. The known affected context is CETIC-6LBR, also called 6lbr, version 1.5.0. No CVSS, CWE, patch commit, or vendor advisory is included in the supplied sources.
Likely exposure
Exposure is most likely in IoT or embedded environments running CETIC-6LBR 1.5.0 with the 6lbr webserver reachable from a 6LoWPAN network. Organizations not using 6LBR, or not exposing this webserver, are unlikely to be affected based on the supplied evidence.
Exploitation context
The CVE is not listed as KEV, and the supplied sources do not show active exploitation. Exploitation would require network access sufficient to send a long URL request to the vulnerable 6LBR webserver over 6LoWPAN.
Researcher notes
The public evidence is sparse but specific: the issue and code reference identify a strcat-driven stack overflow in httpd.c. Missing data includes CVSS, CWE, exploit maturity, exact impact, and fixed release details, so validation should focus on confirming deployment and reachable attack surface.
Mitigation direction
- Inventory any CETIC-6LBR or 6lbr deployments and confirm versions.
- Check project or vendor guidance for a fixed version or recommended patch.
- Restrict access to the 6LBR webserver to trusted network segments.
- Disable the 6LBR webserver if it is not operationally required.
Validation and detection
- Confirm whether CETIC-6LBR 1.5.0 is present in embedded or IoT gateways.
- Verify whether the 6LBR webserver is enabled and reachable over 6LoWPAN.
- Review deployed source or firmware for the referenced httpd.c strcat handling.
- Check logs or telemetry for abnormal long URL requests to the webserver.
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
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CVE-2021-46901 mapping review
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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
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.