Buffer overflow due to unvalidated TCP data offset
Priority MEDIUM 44CWE-120Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-120 and the CVSS impact.
Summary
Contiki-NG is an open-source, cross-platform operating system for internet of things devices. A buffer overflow vulnerability exists in Contiki-NG versions prior to 4.6. After establishing a TCP socket using the tcp-socket library, it is possible for the remote end to send a packet with a data offset that is unvalidated. The problem has been patched in Contiki-NG 4.6. Users can apply the patch for this vulnerability out-of-band as a workaround.
Why it matters now
EPSS 0.00918 60th percentileScored 2026-11-07
Fix Fixed contiki-ng (contiki-ng): 4.6
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| contiki-ng | contiki-ng | before 4.6 | 4.6 | Patch available | CNA |
- contiki-ng Vendorcontiki-ng Affected before 4.6 Fixed in 4.6 Patch available CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:contiki-ng:contiki-ng:*:*:*:*:*:*:*:* | before 4.6 | Vulnerable | contiki-ng |
- cpe:2.3:o:contiki-ng:contiki-ng:*:*:*:*:*:*:*:* Versions before 4.6 Vulnerable ·contiki-ng
Remediation
- Fix · CNA contiki-ng (contiki-ng) Fixed in 4.6
Timeline
- 2026-10-02 Threatist record created from CVE-2021-21281
References
More Contiki-ng vulnerabilities
- TI-2020-14885 An issue was discovered in Contiki through 3.0 and Contiki-NG through 4.5. CVSS 3.1CRITICAL 9.8
- TI-2020-16751 In Contiki 4.5, TCP ISNs are improperly random. CVSS 3.1CRITICAL 9.1
- TI-2018-16029 contiki-ng version 4 contains a Buffer Overflow vulnerability in AQL (Antelope Query… CVSS 3.1CRITICAL 9.8
- TI-2018-13749 An issue was discovered in the MQTT server in Contiki-NG before 4.2. CVSS 3.0CRITICAL 10.0
- TI-2023-14381 Contiki-NG has off-by-one error in Antelope DBMS CVSS 3.1CRITICAL 9.8
- TI-2023-14839 Contiki-NG missing NULL pointer check in IPv6 neighbor discovery CVSS 3.1CRITICAL 9.8
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences