CVE-2021-21279

Infinite loop in IPv6 neighbor solicitation processing

HIGH
7.5
CVSS Score
Published: June 18, 2021 at 08:40 PM UTC
Updated: June 17, 2026 at 03:35 AM UTC
1 product affected across 1 vendorContiki-NG

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Severity
HIGH7.5
Exploit prediction
EPSS 1.0%

Description

Contiki-NG is an open-source, cross-platform operating system for internet of things devices. In verions prior to 4.6, an attacker can perform a denial-of-service attack by triggering an infinite loop in the processing of IPv6 neighbor solicitation (NS) messages. This type of attack can effectively shut down the operation of the system because of the cooperative scheduling used for the main parts of Contiki-NG and its communication stack. 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, and no fixed version or vendor advisory is recorded against it.

CVSS

7.5HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-835

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