# [CRIT] CISA KEV: CVE-2021-27876 — Veritas Backup Exec Agent File Access Vulnerability

**Source:** CISA KEV
**Published:** 2023-04-07
**Article:** https://www.cisa.gov/known-exploited-vulnerabilities-catalog

## Threat Profile

CISA KEV entry. The U.S. federal "Known Exploited Vulnerabilities" catalog only adds CVEs that have been **observed exploited in the wild**. Federal civilian agencies are required to remediate by the published due date; the same prioritisation logic applies to any sensible enterprise SOC.

Vendor / Product: **Veritas Backup Exec Agent File Access**

## Indicators of Compromise

- CVE-2021-27876 — match against your vulnerability scanner

## MITRE ATT&CK

- **T1190 — Exploit Public-Facing Application** (KEV implies active exploitation against exposed assets)

## Recommended hunts

Standard asset-exposure hunt — the canonical Splunk SPL and Defender KQL
live once in [`../_TEMPLATES.md#asset-exposure`](../_TEMPLATES.md#asset-exposure).
Substitute this CVE wherever the template references `<CVE>`:

- **CVE:** `CVE-2021-27876`

## Why this matters

Anything in CISA KEV is *currently* being exploited. Even if your scanners say "not vulnerable" because of patches, it's worth one quick check across your fleet — patch lag is the silent killer. Federal due-date dates also frequently match the timing your organisation will be asked about by auditors / regulators.

## Source body

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. Vendor: Veritas, Product: Backup Exec Agent. Known ransomware use: Known. Federal patch due: 2023-04-28. CVE-2021-27876