# CVE-2021-27878

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.

- Page: https://www.vulneraibility.com/cve/CVE-2021-27878
- CVSS: 8.8
- Known exploited: yes, in CISA KEV since 2023-04-07; CISA due date 2023-04-28; known ransomware use
- EPSS: 23.95% (percentile 97.9)
- Public exploit code: 1 Metasploit module
- CISA SSVC: exploitation active, automatable no, technical impact total (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#issue3
- [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-2021-27878

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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.