CVE-2021-40523

HighCVSS 7.5/10Last modified Jun 17, 2026

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.

Metrics

CVSS 3.1 7.5/10CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Weakness enumeration

CWE-754

Affected software

No affected versions have been published.

Timeline

Published: Sep 5, 2021
Last modified: Jun 17, 2026
NVD status: Modified

Related CVEs from 2021

CVE-2021-405247.5In Pure-FTPd before 1.0.50, an incorrect max_filesize quota mechanism in the server allows attackers to upload files of unbounded size, whic CVE-2021-405259.1Apache James ManagedSieve implementation alongside with the file storage for sieve scripts is vulnerable to path traversal, allowing reading CVE-2021-405265.3Incorrect calculation of buffer size vulnerability in Peleton TTR01 up to and including PTV55G allows a remote attacker to trigger a Denial CVE-2021-405277.5Exposure of senstive information to an unauthorised actor in the "com.onepeloton.erlich" mobile application up to and including version 1.7.CVE-2021-405285.9The ElGamal implementation in Libgcrypt before 1.9.4 allows plaintext recovery because, during interaction between two cryptographic librari CVE-2021-405295.9The ElGamal implementation in Botan through 2.18.1, as used in Thunderbird and other products, allows plaintext recovery because, during int CVE-2021-40538.8Use after free in UI in Google Chrome on Linux prior to 96.0.4664.93 allowed a remote attacker to potentially exploit heap corruption via a CVE-2021-405305.9The ElGamal implementation in Crypto++ through 8.5 allows plaintext recovery because, during interaction between two cryptographic libraries CVE-2021-405319.8Sketch before 75 allows library feeds to be used to bypass file quarantine. Files are automatically downloaded and opened, without the com.a CVE-2021-405329.8Telegram Web K Alpha before 0.7.2 mishandles the characters in a document extension.CVE-2021-405372.7Server Side Request Forgery (SSRF) vulnerability exists in owncloud/user_ldap < 0.15.4 in the settings of the user_ldap app. Administration CVE-2021-405399.8Zoho ManageEngine ADSelfService Plus version 6113 and prior is vulnerable to REST API authentication bypass with resultant remote code execu