CVE-2021-27878

CVE-2021-27878 is a high-severity vulnerability in Veritas Backup Exec with a CVSS 3.x base score of 8.8. 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. The attacker could use one of these commands to execute an arbitrary command on the system using system privileges.

Frequently asked questions

What is 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.
How severe is CVE-2021-27878?
CVE-2021-27878 has a CVSS 3.x base score of 8.8, 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 high.
Is CVE-2021-27878 being actively exploited?
Yes. CVE-2021-27878 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-2021-27878?
CVE-2021-27878 affects Veritas Backup Exec. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-27878?
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-2021-27878 have an EU (EUVD) identifier?
Yes. CVE-2021-27878 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-14616. It is also flagged as exploited in the EUVD (since 2023-04-07).
When was CVE-2021-27878 published?
CVE-2021-27878 was published on 2021-03-01 and last updated on 2026-06-17.

References

Affected products (1)

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