Contiki-NG tinyDTLS Buffer Over-Read / Denial Of Service

[Suggested description]An issue was discovered in Contiki-NG tinyDTLS through 2018-08-30. A buffer over-read exists in the dtls_sha256_update function. This bug allows remote attackers to cause a denial of service (crash) and possibly read sensitive information by sending a malformed packet with an over-large fragment length field, due to servers incorrectly handling malformed packets.[Vulnerability Type]Buffer Overflow[Vendor of Product]https://github.com/contiki-ng/tinydtls[Affected Product Code Base]contiki-ng tinydtls - master branch 53a0d97[Affected Component]the service of dtls servers[Attack Type]Remote[Impact Code execution]true[Impact Denial of Service]true[Reference]https://github.com/contiki-ng/tinydtls/issues/21[Discoverer]jerrytesting[CVE Reference]The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CVE-2021-42147 to this vulnerability.