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Findings

CVE-2021-27876

Veritas Backup Exec Agent File Access Vulnerability

Published Mar 1, 2021 · updated Jun 16, 2026 · veritas backup exec

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.

Timeline

Detection, updates, and resolution for this record.

  1. Mar 1, 2021 · Catalog

    Detected

    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 da

  2. Apr 7, 2023 · CISA KEV

    Known exploited

    Apply updates per vendor instructions.

  3. Apr 28, 2023 · CISA KEV

    Remediation due

    Apply updates per vendor instructions.

  4. Jun 16, 2026 · Catalog

    Updated

    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 da

Required action

Apply updates per vendor instructions.

CISA due date Apr 28, 2023

Affected

  • cpe veritas/backup execversion unspecified
  • vendor Veritas Backup Exec Agentversion unspecified

Sources

  • CISA KEVCVE-2021-27876

    Veritas Backup Exec (BE) Agent contains a file access vulnerability that could allow an attacker to specially craft input parameters on a data management protocol command to access files on the BE Agent machine.

    cisa.gov
  • CVE.orgCVE-2021-27876

    Official CVE identifier

    cve.org
  • FIRST EPSSCVE-2021-27876

    30-day exploitation probability 13.5%

    first.org
  • Metasploit Modulesexploit_multi/veritas/beagent_sha_auth_rce

    Public module reference (excellent). Module source is not copied into this catalog.

    rapid7.com
  • NIST NVDCVE-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 attac

    nvd.nist.gov
  • Packet Storm Securityhttp://packetstormsecurity.com/files/168506/Veritas-Backup-Exec-Agent-Remote-Code-Execution.html

    Packet Storm link already published on the finding.

    packetstormsecurity.com

References

CVE-2021-27876 · ZeroDay Findings