CVE-2021-27877Veritas Backup Exec Agent Improper Authentication Vulnerability

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.

9.8 CRITICALEPSS 64.91%⚡ Known Exploited (CISA KEV)NVD: Analyzed

Last updated: 2026-06-17 03:45 UTC

OverviewCVSS details

9.8CRITICALCVSS 3.1

Score source: NVD
NVD status: Analyzed
Published: Mar 1, 2021
Assigner: mitre

Affected

backup exec (veritas)

Versions: before 21.2
Fixed in: 21.2

Exploitation

Public exploit: Yes · 1 reference
CISA KEV: Listed · Apr 7, 2023
KEV due date: Apr 28, 2023
Ransomware use: Known
SSVC: Exploitation active · Automatable yes · Impact partial

EPSS · FIRST, scored Nov 8

64.91%chance of exploitation in 30 days

Higher than 99.25% of CVEs

CVSS 3.1 · NVD

9.8Critical

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

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: High

CVSS 3.1 · mitre (CNA)

8.2High

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

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: Low
Availability impact: None

CVSS 3.1 · mitre (CNA)

8.2High

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

Attack complexity: Low
Attack vector: Network
Availability impact: None
Confidentiality impact: High
Integrity impact: Low
Privileges required: None
Scope: Unchanged
User interaction: None

CVSS 2.0 · NVD

7.5High

AV:N/AC:L/Au:N/C:P/I:P/A:P

Attack vector: Network
Attack complexity: Low
Authentication: None
Confidentiality impact: Partial
Integrity impact: Partial
Availability impact: Partial

NVD status: Analyzed

Overview Affected Products References

NVD CVE.org

Overview

Severity

Score	Severity	Version	Vector String
9.8	CRITICAL	3.1NVD	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
8.2	HIGH	3.1mitre (CNA)	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
8.2	HIGH	3.1mitre (CNA)	CVSS:3.1/AC:L/AV:N/A:N/C:H/I:L/PR:N/S:U/UI:N
7.5	HIGH	2.0NVD	AV:N/AC:L/Au:N/C:P/I:P/A:P

CISA required action

⚡ Known exploited · remediation due Apr 28, 2023

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Details

CVE ID: CVE-2021-27877
Status: Analyzed
Assigner (CNA): mitre
Published: Mar 1, 2021
Last modified: 2026-06-17 03:45 UTC
Weaknesses: CWE-287

Sources

Refreshed hourly from the sources above. Last fetched 2026-11-08 14:59 UTC.