VULNERABILITY INTELLIGENCE

CVE-2021-40523

CVSS score7.5 HIGH
EPSS probability0.96%
CISA KEVNot currently listed
Published2021-09-05
Last modified2026-06-17
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Description

In Contiki 3.0, Telnet option negotiation is mishandled. During negotiation between a server and a client, the server may fail to give the WILL/WONT or DO/DONT response for DO and WILL commands because of improper handling of exception condition, which leads to property violations and denial of service. Specifically, a server sometimes sends no response, because a fixed buffer space is available for all responses and that space may have been exhausted.

Weakness classification

  • nvd@nist.gov: CWE-754

Primary references