CVE-2021-27877 : An issue was discovered in Veritas Backup Exec before 21.2. It supports multiple

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.

Published 2021-03-01 22:15:14

Updated 2022-09-27 20:15:04

Source MITRE

View at NVD, CVE.org

Vulnerability category: BypassGain privilege

Products affected by CVE-2021-27877

Veritas » Backup Exec
Versions before (<) 21.2
cpe:2.3:a:veritas:backup_exec:*:*:*:*:*:*:*:*
Matching versions

CVE-2021-27877 is in the CISA Known Exploited Vulnerabilities Catalog

This issue is known to have been leveraged as part of a ransomware campaign.

CISA vulnerability name:

Veritas Backup Exec Agent Improper Authentication Vulnerability

CISA required action:

Apply updates per vendor instructions.

CISA description:

Veritas Backup Exec (BE) Agent contains an improper authentication vulnerability that could allow an attacker unauthorized access to the BE Agent via SHA authentication scheme.

Notes:

https://www.veritas.com/support/en_US/security/VTS21-001; https://nvd.nist.gov/vuln/detail/CVE-2021-27877

Added on 2023-04-07 Action due date 2023-04-28

Exploit prediction scoring system (EPSS) score for CVE-2021-27877

EPSS FAQ

76.21%

Probability of exploitation activity in the next 30 days EPSS Score History

~ 98 %

Percentile, the proportion of vulnerabilities that are scored at or less

Metasploit modules for CVE-2021-27877

Veritas Backup Exec Agent Remote Code Execution

Disclosure Date: 2021-03-01

First seen: 2022-12-23

exploit/multi/veritas/beagent_sha_auth_rce

Authors: - Alexander Korotin <0xc0rs@gmail.com>

More information

CVSS scores for CVE-2021-27877

Base Score	Base Severity	CVSS Vector	Exploitability Score	Impact Score	Score Source
7.5	HIGH	AV:N/AC:L/Au:N/C:P/I:P/A:P	10.0	6.4	NIST
Access Vector: Network Access Complexity: Low Authentication: None Confidentiality Impact: Partial Integrity Impact: Partial Availability Impact: Partial
8.2	HIGH	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N	3.9	4.2	MITRE
Attack Vector: Network Attack Complexity: Low Privileges Required: None User Interaction: None Scope: Unchanged Confidentiality: High Integrity: Low Availability: None
9.8	CRITICAL	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H	3.9	5.9	NIST
Attack Vector: Network Attack Complexity: Low Privileges Required: None User Interaction: None Scope: Unchanged Confidentiality: High Integrity: High Availability: High

CWE ids for CVE-2021-27877

CWE-287 Improper Authentication

When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.

Assigned by: nvd@nist.gov (Primary)

References for CVE-2021-27877

https://www.veritas.com/content/support/en_US/security/VTS21-001#issue1

Security Advisory for Backup Exec version 21.2 | Veritas™
Vendor Advisory
http://packetstormsecurity.com/files/168506/Veritas-Backup-Exec-Agent-Remote-Code-Execution.html

Veritas Backup Exec Agent Remote Code Execution ≈ Packet Storm
Exploit;Third Party Advisory;VDB Entry

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Vulnerability Details : CVE-2021-27877