How severe is CVE-2021-27877?

CVE-2021-27877 has a CVSS 3.x base score of 8.2, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity low, and availability none.

Is CVE-2021-27877 being actively exploited?

Yes. CVE-2021-27877 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-2021-27877?

CVE-2021-27877 affects Veritas Backup Exec. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-27877?

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-2021-27877 have an EU (EUVD) identifier?

Yes. CVE-2021-27877 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-14615. It is also flagged as exploited in the EUVD (since 2023-04-07).

When was CVE-2021-27877 published?

CVE-2021-27877 was published on 2021-03-01 and last updated on 2026-06-17.

CVE-2021-27877

CVE-2021-27877 is a high-severity vulnerability in Veritas Backup Exec with a CVSS 3.x base score of 8.2. 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

Severity: High (CVSS 3.x base score 8.2)
CVSS v2: 7.5
EPSS exploit prediction: 65% (99th percentile)
Actively exploited: Yes — listed in CISA KEV (added 2023-04-07)
EU (EUVD) id: EUVD-2021-14615
EU exploitation: Flagged exploited in the ENISA EU Vulnerability Database (since 2023-04-07)
Affected product: Veritas Backup Exec
Published: 2021-03-01
Last modified: 2026-06-17

Description

An issue was discovered in Veritas Backup Exec before 21.2. It supports multiple authentication schemes: SHA authentication is one of these. This authentication scheme is no longer used in current versions of the product, but hadn't yet been disabled. An attacker could remotely exploit this scheme to gain unauthorized access to an Agent and execute privileged commands.

Frequently asked questions

What is CVE-2021-27877?: An issue was discovered in Veritas Backup Exec before 21.2. It supports multiple authentication schemes: SHA authentication is one of these. This authentication scheme is no longer used in current versions of the product, but hadn't yet been disabled. An attacker could remotely exploit this scheme to gain unauthorized access to an Agent and execute privileged commands.
How severe is CVE-2021-27877?: CVE-2021-27877 has a CVSS 3.x base score of 8.2, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity low, and availability none.
Is CVE-2021-27877 being actively exploited?: Yes. CVE-2021-27877 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-2021-27877?: CVE-2021-27877 affects Veritas Backup Exec. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-27877?: 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-2021-27877 have an EU (EUVD) identifier?: Yes. CVE-2021-27877 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-14615. It is also flagged as exploited in the EUVD (since 2023-04-07).
When was CVE-2021-27877 published?: CVE-2021-27877 was published on 2021-03-01 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:veritas:backup_exec:*:*:*:*:*:*:*:*

More vulnerabilities in Veritas Backup Exec

CVE-2017-8895 — Critical (CVSS 9.8): In Veritas Backup Exec 2014 before build 14.1.1187.1126, 15 before build 14.2.1180.3160, and 16 before FP1, there is a…
CVE-2020-36167 — Critical (CVSS 9.3): An issue was discovered in the server in Veritas Backup Exec through 16.2, 20.6 before hotfix 298543, and 21.1 before…
CVE-2021-27878 — High (CVSS 8.8): An issue was discovered in Veritas Backup Exec before 21.2. The communication between a client and an Agent requires…
CVE-2021-27876 — High (CVSS 8.1): An issue was discovered in Veritas Backup Exec before 21.2. The communication between a client and an Agent requires…
CVE-2024-33673 — High (CVSS 7.8): An issue was discovered in Veritas Backup Exec before 22.2 HotFix 917391. Improper access controls allow for DLL…
CVE-2024-33671 — High (CVSS 7.7): An issue was discovered in Veritas Backup Exec before 22.2 HotFix 917391. The Backup Exec Deduplication Multi-threaded…

All CVEs affecting Veritas Backup Exec →