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[ CVE-2021-27876 · Published 1 Mar 2021 ]

Veritas Backup Exec Agent File Access Vulnerability

Exploited · CISA KEV CVSS 8.1 EPSS 14%No fix listed yet

[ Why it matters ]Priority signals

  • Exploited in the wild: on CISA's Known Exploited Vulnerabilities list since 2023-04-07
  • Known to be used in ransomware campaigns
  • EPSS: 14% chance of exploitation in the next 30 days (higher than 96% of CVEs)

[ Description ]Official 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. By using crafted input parameters in one of these commands, an attacker can access an arbitrary file on the system using System privileges.

CISA: 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.

[ Fixes ]Fixes and patches

CISA required action (US federal deadline 28 Apr 2023): Apply updates per vendor instructions.

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ References ]References