# CVE-2021-27877

An issue was discovered in Veritas Backup Exec before 21.2. It supports multiple authentication schemes: SHA authentication is one of these. This authentication scheme is no longer used in current versions of the product, but hadn't yet been disabled. An attacker could remotely exploit this scheme to gain unauthorized access to an Agent and execute privileged commands.

- Page: https://www.vulneraibility.com/cve/CVE-2021-27877
- CVSS: 8.2
- Known exploited: yes, in CISA KEV since 2023-04-07; CISA due date 2023-04-28; known ransomware use
- EPSS: 64.91% (percentile 99.3)
- Public exploit code: 1 Metasploit module · 1 GitHub proof of concept · 1 Nuclei template (first 2026-07-02)
- CISA SSVC: exploitation active, automatable yes, technical impact partial (assessed 2023-12-22)
- Published: 2021-03-01

## Affected

- veritas:backup_exec

## References

- [other] https://www.veritas.com/content/support/en_US/security/VTS21-001#issue1
- [other] http://packetstormsecurity.com/files/168506/Veritas-Backup-Exec-Agent-Remote-Code-Execution.html
- [other] https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-27877

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Summary, impact and action are written by the vulneraibility.com AI analysis pipeline from the CVE record, NVD, CISA and FIRST data; verify against the references.