CVE-2021-40523 Denial of service in n/a
A flaw in Contiki OS Telnet negotiation handling can cause a denial of service by exhausting response buffers.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2021-40523?
CVE-2021-40523 is a high-severity denial of service vulnerability in n/a, published on 5 Sep 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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: CWE-754
Which versions are affected by CVE-2021-40523?
It affects 1 product.
Products include Contiki-Os Contiki.
How do I fix CVE-2021-40523?
No fix has been published for CVE-2021-40523 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2021-40523 being exploited?
There is no known exploitation of CVE-2021-40523 in the wild and no public exploit code.
Other vulnerabilities in n/a
Sources
Also known as GHSA-9rqj-h33r-qgm8.