CVE-2021-27877
Veritas Backup Exec Agent Improper Authentication Vulnerability
Does this matter?
Known to be exploited in the wild (CISA KEV, CISA remediation deadline 28 April 2023). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.
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.
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 64.91% probability · 99th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Listed 7 April 2023 · due 28 April 2023 · used in ransomware campaigns
- Affected
- veritas/backup exec
- Source
- cve@mitre.org
EPSS 64.9% since 30 October 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
CISA notes
Apply updates per vendor instructions. https://www.veritas.com/support/en_US/security/VTS21-001; https://nvd.nist.gov/vuln/detail/CVE-2021-27877
References
- http://packetstormsecurity.com/files/168506/Veritas-Backup-Exec-Agent-Remote-Code-Execution.htmlExploit, Third Party Advisory, VDB Entry
- https://www.veritas.com/content/support/en_US/security/VTS21-001#issue1Vendor Advisory
- http://packetstormsecurity.com/files/168506/Veritas-Backup-Exec-Agent-Remote-Code-Execution.htmlExploit, Third Party Advisory, VDB Entry
- https://www.veritas.com/content/support/en_US/security/VTS21-001#issue1Vendor Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-27877US Government Resource
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.