Provide references for CVE-2021-28838.
Where can I find more information about CVE-2021-28838?
References are available at: https://www.dlink.com/en/security-bulletin/, https://github.com/zyw-200/EQUAFL/blob/main/dlink-email-cve.pdf, https://github.com/zyw-200/EQUAFL/blob/main/dlink-email-cve2.pdf.