CVE-2021-27878

CVE-2021-27878 is a critical authentication bypass vulnerability affecting Veritas Backup Exec before version 21.2. This flaw allows an authenticated attacker to bypass the SHA authentication scheme, gain unauthorized access to the Backup Exec Agent, and subsequently execute arbitrary commands with system privileges. With a CVSS score of 8.8 (High), the vulnerability is easily exploitable over the network with low privileges and no user interaction, leading to complete compromise of confidentiality, integrity, and availability. This CVE is actively exploited in the wild, notably by the ALPHV (BlackCat) ransomware group, and has publicly available Metasploit modules, indicating a high risk and widespread community attention.