CVE-2021-21280

Out-of-bounds write when processing 6LoWPAN extension headers

CRITICAL
9.8
CVSS Score
Published: June 18, 2021 at 08:35 PM UTC
Updated: June 17, 2026 at 03:35 AM UTC
1 product affected across 1 vendorContiki-NG

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Severity
CRITICAL9.8
Exploit prediction
EPSS 1%

Description

Contiki-NG is an open-source, cross-platform operating system for internet of things devices. It is possible to cause an out-of-bounds write in versions of Contiki-NG prior to 4.6 when transmitting a 6LoWPAN packet with a chain of extension headers. Unfortunately, the written header is not checked to be within the available space, thereby making it possible to write outside the buffer. The problem has been patched in Contiki-NG 4.6. Users can apply the patch for this vulnerability out-of-band as a workaround.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 4.6
Affected range stops below 4.6, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (2)

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-787

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