CVE-2021-27876

CVE-2021-27876 is a high-severity vulnerability in Veritas Backup Exec with a CVSS 3.x base score of 8.1. It is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, confirming it has been exploited in the wild (added 2023-04-07).

Key facts

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.

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.
How severe is CVE-2021-27876?
CVE-2021-27876 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2021-27876 being actively exploited?
Yes. CVE-2021-27876 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2023-04-07, which means active exploitation has been confirmed. It should be prioritised for remediation.
What products are affected by CVE-2021-27876?
CVE-2021-27876 affects Veritas Backup Exec. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-27876?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.
Does CVE-2021-27876 have an EU (EUVD) identifier?
Yes. CVE-2021-27876 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-14614. It is also flagged as exploited in the EUVD (since 2023-04-07).
When was CVE-2021-27876 published?
CVE-2021-27876 was published on 2021-03-01 and last updated on 2026-06-17.

References

Affected products (1)

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