How severe is CVE-2021-27876?

CVE-2021-27876 has a CVSS 3.1 base score of 8.1 (HIGH). EPSS estimates a 13.5% probability of exploitation in the next 30 days. It is listed in the CISA Known Exploited Vulnerabilities catalog.

CVE-2021-27876: Veritas Backup Exec Agent File Access

CISA Known Exploited Vulnerabilities

Veritas Backup Exec Agent File Access Vulnerability is confirmed as actively exploited and is listed in the CISA KEV catalog.

Added to KEV

2023-04-07

Remediation due

2023-04-28

Ransomware

Known use

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 · CNA8.1 HIGH

CVSS:3.1/AC:L/AV:N/A:N/C:H/I:H/PR:L/S:U/UI:N

SSVC · CISA-ADP

Exploitationactive

Automatableno

Technical impacttotal

Affected Products

Vendor	Product	Affected versions
-	-	n/a

References

2 Links

Other references

Record Details

Published

2021-03-01

Last updated

2025-10-21

Assigner (CNA)

mitre

Credited to

CVE record data © The MITRE Corporation, used under the CVE Terms of Use. Exploited-in-the-wild data from the CISA Known Exploited Vulnerabilities catalog (CC0). Exploit prediction scores by FIRST EPSS (first.org/epss). This site is not endorsed or certified by MITRE, NVD, CISA, or FIRST.