{"id":"CVE-2021-27876","url":"https://www.cyber-defence.io/tools/cve/CVE-2021-27876","generatedAt":"2026-10-27T21:20:11.019Z","title":"Veritas Backup Exec Agent File Access Vulnerability","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.","published":"2021-03-01T22:15:14.000Z","lastModified":"2026-06-17T03:45:33.000Z","status":"Analyzed","sourceIdentifier":"cve@mitre.org","cvss":{"version":"3.1","score":8.1,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N"},"cwe":[],"affected":["veritas/backup exec"],"epss":{"score":0.13518,"percentile":0.96424,"date":"2026-10-26","history":[]},"kev":{"listed":true,"dateAdded":"2023-04-07","dueDate":"2023-04-28","knownRansomwareCampaignUse":"Known","notes":"Apply updates per vendor instructions.\nhttps://www.veritas.com/support/en_US/security/VTS21-001; https://nvd.nist.gov/vuln/detail/CVE-2021-27876"},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"urgent","text":"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."},"changes":[],"references":[{"url":"http://packetstormsecurity.com/files/168506/Veritas-Backup-Exec-Agent-Remote-Code-Execution.html","tags":["Exploit","Third Party Advisory","VDB Entry"],"source":"cve@mitre.org"},{"url":"https://www.veritas.com/content/support/en_US/security/VTS21-001#issue2","tags":["Vendor Advisory"],"source":"cve@mitre.org"},{"url":"http://packetstormsecurity.com/files/168506/Veritas-Backup-Exec-Agent-Remote-Code-Execution.html","tags":["Exploit","Third Party Advisory","VDB Entry"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.veritas.com/content/support/en_US/security/VTS21-001#issue2","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-27876","tags":["US Government Resource"],"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-27876","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}