CVEs / CVE-2021-27876
CVE-2021-27876: Veritas Backup Exec Agent File Access Vulnerability
- Known exploited in the CISA KEV catalog since 7 Apr 2023
- high 8.1 CVSS 3.1 (NVD)
- EPSS 13.5% chance of exploitation in the next 30 days, higher than 96% of CVEs (30 Oct 2026)
- Last changed at its sources
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Summary
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.
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.
Affected and fixed versions
| Product | Affected | Fixed in |
|---|---|---|
| n/a n/a | n/a | — |
Exploitation
| In CISA KEV since | 7 Apr 2023 |
|---|---|
| Due date for US federal agencies | 28 Apr 2023 |
| Used in ransomware campaigns | Known |
| Required action | Apply updates per vendor instructions. |
Severity
| CVSS 3.1 | 8.1 highCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:NScored by NVD |
|---|
References
- CVE-2021-27876 on NVD
- CVE-2021-27876 in the CISA KEV catalog
- https://www.veritas.com/support/en_US/security/VTS21-001 (cited by CISA)
- 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#issue2 Vendor Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-27876 US Government Resource
Sources
Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.
This product uses data from the NVD API but is not endorsed or certified by the NVD.