HIGH CISA KEV

CVE-2021-27876

CVSS v3

8.1

HIGH

EPSS Score

1.0%

exploit probability

CISA KEV

Yes

known exploited

Exploitation

SSVC status

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.

CISA Known Exploited Vulnerability

Date Added
4/7/2023
Patch Due Date
4/28/2023
Ransomware Use
Known

Technical details

Published
3/1/2021

Frequently asked questions

What is CVE-2021-27876?

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.

Is CVE-2021-27876 actively exploited?

Yes. CVE-2021-27876 is on the CISA Known Exploited Vulnerabilities (KEV) catalog, meaning it has been confirmed as actively exploited in the wild. CISA requires federal agencies to patch by 4/28/2023.

What is the CVSS score for CVE-2021-27876?

CVE-2021-27876 has a CVSS v3 base score of 8.1 (HIGH severity).

Is CVE-2021-27876 affecting your environment?

Use isMalicious to check if any of your IPs or domains are associated with this vulnerability's IOCs.