CVE-2021-40523
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.96%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 0.96% probability · 60th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-754
- Affected
- contiki-os/contiki
- Source
- cve@mitre.org
References
- https://github.com/contiki-os/contiki/issues/2686Patch, Third Party Advisory
- https://github.com/contiki-os/contiki/issues/2686Patch, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.