CVE DATABASE / CVE-2021-27878
CVE-2021-27878
Veritas Backup Exec Agent Command Execution Vulnerability
Confirmed exploited in the wild. Added 2023-04-07.
Federal remediation due 2023-04-28.
Required action: Apply updates per vendor instructions.
Summary
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.
CVSS 3.1 breakdown
| Base score | 8.8 (HIGH) |
| Vector | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| Attack vector | NETWORK |
| Attack complexity | LOW |
| Privileges required | LOW |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | HIGH |
| Integrity | HIGH |
| Availability | HIGH |
Affected products
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References
- http://packetstormsecurity.com/files/168506/Veritas-Backup-Exec-Agent-Remote-Code-Execution.html
- https://www.veritas.com/content/support/en_US/security/VTS21-001#issue3
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-27878
Data: NIST NVD + CISA KEV. NVD last modified 2025-11-03. Always verify against the vendor advisory before acting.