# CVE-2021-27877: Veritas Backup Exec Agent Improper Authentication Vulnerability

Source: https://junglewise.ai/threats/cve-2021-27877-veritas-backup-exec-agent-improper-authentication-vulnerability  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2023-04-07. Updated: 2026-05-10  
License: CC BY 4.0 with a link back

CVE-2021-27877 · Severity: critical · CVSS 9.8 · Exploited in the wild · Published 2023-04-07

Veritas Backup Exec Agent contains an improper authentication vulnerability due to the continued support of a legacy SHA authentication scheme. Remote attackers can exploit this scheme to bypass authentication and execute privileged commands on the affected Agent.

Technologies: [Veritas Backup Exec Agent](https://junglewise.ai/threats/technologies/backup-exec-agent). Vendors: [Veritas](https://junglewise.ai/threats/vendors/veritas).

## Quick answers

**Is CVE-2021-27877 exploited in the wild?** Yes. CVE-2021-27877 is known to be exploited in the wild, first recorded on 7 April 2023. Treat it as urgent.

**How severe is CVE-2021-27877?** Critical severity, with a CVSS score of 9.8, published 7 April 2023.

**Which products and versions are affected?** Veritas Backup Exec Agent before 21.2.

**Is there a fix for CVE-2021-27877?** A patch was published on 2021-03-01: Fixed in version 21.2 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2021-27877 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2021-27877?** Check whether you run Veritas Backup Exec Agent. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Affected products

- Veritas Backup Exec Agent before 21.2

## Timeline

- 2021-03-01: disclosed: NVD Published Date
- 2023-04-07: kev added: Added to CISA Known Exploited Vulnerabilities Catalog
- 2021-03-01: patched: Fixed in version 21.2
- 2023-04-07: exploited: Reported as exploited in the wild per CISA KEV catalog entry date

## Related threats

- [Veritas Backup Exec Agent Command Execution Vulnerability](https://junglewise.ai/threats/cve-2021-27878-veritas-backup-exec-agent-command-execution-vulnerability)
- [Veritas Backup Exec Agent File Access Vulnerability](https://junglewise.ai/threats/cve-2021-27876-veritas-backup-exec-agent-file-access-vulnerability)