CVE-2021-42564

CVE-2021-42564 describes an open redirect vulnerability affecting Cryptshare Server versions prior to 5.1.0. This flaw allows an authenticated attacker, with permission to send confidential messages, to inject HTML containing a meta refresh tag into the editor parameter. This injection can redirect a targeted victim to an arbitrary URL. The vulnerability has a CVSS score of 5.4 (Medium), indicating a network-based attack requiring low privileges and user interaction, leading to low confidentiality and integrity impacts. While the attack complexity is low, it requires social engineering to trick the user into clicking the malicious link. Currently, there is no evidence of active exploitation, and no public exploit code is available in Metasploit, Nuclei, or ExploitDB. Community discussion and media coverage for this CVE are minimal, suggesting it has not garnered significant attention.