CVE-2021-27876
Veritas Backup Exec Agent File Access Vulnerability is confirmed as actively exploited and is listed in the CISA KEV catalog.
Required action
Apply updates per vendor instructions.
CISA notes
https://www.veritas.com/support/en_US/security/VTS21-001; https://nvd.nist.gov/vuln/detail/CVE-2021-27876
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. By using crafted input parameters in one of these commands, an attacker can access an arbitrary file on the system using System privileges.
Severity
CVSS:3.1/AC:L/AV:N/A:N/C:H/I:H/PR:L/S:U/UI:NExploitation Context
as of October 13, 2026- CISA added CVE-2021-27876 to the KEV catalog 767 days after its CVE record was published. The median for entries added in 2023 is 12 days.
- It is one of 3 Veritas entries in the CISA KEV catalog, and one of 3 added in 2023.
- Its current EPSS score (13.5%) is higher than that of 29% of CISA KEV entries.
Affected Products
| Vendor | Product | Affected versions |
|---|---|---|
| - | - | n/a |
References
2 LinksRecord Details
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