CVE-2021-27878: Veritas Backup Exec Agent Command Execution Vulnerability

Vulnerability summary

CVE-2021-27878 is a high (CVSS 9.0) vulnerability in Veritas Backup Exec Agent. It is known to be exploited: CISA lists it, first on 07-04-2023. It has been used in ransomware campaigns. EPSS estimates a 23.95% chance of exploitation in the next 30 days, higher than 97.8% of scored vulnerabilities. 2 public exploits are recorded.

Timeline

1. 01-03-2021
   PublishedVulnerability first disclosed.
2. 07-04-2023
   Added to CISA KEVVeritas Backup Exec Agent Command Execution Vulnerability
3. 28-04-2023
   CISA remediation dueApply updates per vendor instructions.
4. 21-10-2025
   Last modifiedVulnerability information updated.

Description

An issue was discovered in Veritas Backup Exec before 21.2. The communication between a client and an Agent requires successful authentication, which is typically completed over a secure TLS communication. However, due to a vulnerability in the SHA Authentication scheme, an attacker is able to gain unauthorized access and complete the authentication process. Subsequently, the client can execute data management protocol commands on the authenticated connection. The attacker could use one of these commands to execute an arbitrary command on the system using system privileges.

No weakness data has been published for this record.