CVE-2021-27877: Veritas Backup Exec Agent Improper Authentication Vulnerability
Reference page built from the source records below, each shown as its source publishes it. Dataset version ref-4684466fda1d, updated 2026-11-02T23:39:54.475Z.
CISA Known Exploited Vulnerabilities
- Name
- Veritas Backup Exec Agent Improper Authentication Vulnerability
- Vendor
- Veritas
- Product
- Backup Exec Agent
- Added to the catalog
- 2023-04-07
- Due date for US federal agencies
- 2023-04-28
- Weaknesses
- CWE-287
- Catalog version
- 2026.10.30
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.
Required action (CISA)
Apply updates per vendor instructions.
Ransomware use: CISA marks this vulnerability as known to be used in ransomware campaigns. CISA does not say which group used it.
Links in CISA's notes
- https://www.veritas.com/support/en_US/security/VTS21-001
- https://nvd.nist.gov/vuln/detail/CVE-2021-27877
Read on 2026-11-02T23:39:54.475Z under licence cisa-kev-cc0@b0067899 from https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json
NVD analysis
- Status
- Analyzed
- Published
- 2021-03-01T22:15:14.460
- Last modified
- 2026-06-17T03:45:32.920
- Weaknesses
- NVD-CWE-noinfo
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.
| Metric | Score | Severity | Vector | Scored by |
|---|---|---|---|---|
| CVSS 3.1 | 8.2 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N | [email protected] (Secondary) |
| CVSS 3.1 | 9.8 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H | [email protected] (Primary) |
| CVSS 2.0 | 7.5 | HIGH | AV:N/AC:L/Au:N/C:P/I:P/A:P | [email protected] (Primary) |
References
- http://packetstormsecurity.com/files/168506/Veritas-Backup-Exec-Agent-Remote-Code-Execution.html (Exploit, Third Party Advisory, VDB Entry)
- https://www.veritas.com/content/support/en_US/security/VTS21-001#issue1 (Vendor Advisory)
- http://packetstormsecurity.com/files/168506/Veritas-Backup-Exec-Agent-Remote-Code-Execution.html (Exploit, Third Party Advisory, VDB Entry)
- https://www.veritas.com/content/support/en_US/security/VTS21-001#issue1 (Vendor Advisory)
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-27877 (US Government Resource)
This product uses the NVD API but is not endorsed or certified by the NVD.
Read on 2026-11-02T23:41:51.476Z under licence nvd-api-terms-of-use@ff2a5288 from https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2021-27877
CVE record
- Assigner
- mitre
- State
- PUBLISHED
- Published
- 2021-03-01T21:49:36.000Z
- Updated
- 2025-10-21T23:25:53.349Z
- Problem types
- n/a
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.
References
- https://www.veritas.com/content/support/en_US/security/VTS21-001#issue1
- http://packetstormsecurity.com/files/168506/Veritas-Backup-Exec-Agent-Remote-Code-Execution.html
Read on 2026-11-03T01:07:11.203Z under licence cve-terms-of-use@81bfa2f3 from https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2021/27xxx/CVE-2021-27877.json
Sources and licences
CISA
Source: CISA Catalog of Known Exploited Vulnerabilities, version 2026.10.30, CC0 1.0. Use of this data does not imply endorsement by CISA or DHS.
National Vulnerability Database (NIST)
This product uses the NVD API but is not endorsed or certified by the NVD.
NVD API Terms of Use (NIST publications in the public domain, 17 U.S.C. 105)
CVE Program, The MITRE Corporation
Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation. CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy.
Cite this page
Dragons Eye Ransomware Tracker, "CVE-2021-27877: Veritas Backup Exec Agent Improper Authentication Vulnerability",
entity page, dataset version ref-4684466fda1d, updated 2026-11-02T23:39:54.475Z,
https://ransomware-tracker.com/cve/CVE-2021-27877 (accessed 2026-11-03).
Underlying source: CISA Catalog of Known Exploited Vulnerabilities, version 2026.10.30.
Underlying source: National Vulnerability Database (NIST), CVE API 2.0, record last modified 2026-06-17T03:45:32.920.
Underlying source: CVE List (CVE Program, The MITRE Corporation), record updated 2025-10-21T23:25:53.349Z.
Pages change. The dataset version identifies the data, but no archive of old versions is kept, so this citation cannot be replayed later.