Vulnerability

CVE-2021-27877

High· 8.2KEVEXPLOITCVSS8.2EPSS40%

.rules3/5

Veritas Backup Exec Agent Improper Authentication Vulnerability

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.

Threat signal

100/100

Severe

Severity

high

CVSS

8.2

EPSS

40%

Active

KEV

CISA KEV — actively exploited

Ransomware: Known1142d overdue

AffectedVeritas — Backup Exec Agent

Added to KEV

2023-04-07

Federal patch due (BOD 22-01)

2023-04-28

Required action (CISA verbatim)

Apply updates per vendor instructions.

Vendor advisory + references

CISA description: “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.”

CVSS

v3.1Open in FIRST calculator →

8.2/ 10HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

Attack VectorNetworkExploitable remotely over the internet — no local access needed.
Attack ComplexityLowNo special conditions — exploit works reliably.
Privileges RequiredNoneUnauthenticated — no credentials needed.
User InteractionNoneFully automated — no victim action needed.
ScopeUnchangedImpact contained to the vulnerable component.
Confidentiality ImpactHighTotal disclosure of sensitive data.
Integrity ImpactLowSome data modification; attacker doesn't fully control extent.
Availability ImpactNoneNo availability impact.

EPSS

Exploit prediction · 30-day horizonFIRST.org →

40.3%

probability of exploitation in next 30 days

p97

higher than 97% of all CVEs

3-day trend↑ 0pp

Above the FIRST 'patch on a priority schedule' threshold.

Vendor VEX

No VEX statements published for CVE-2021-27877. Vendors publish VEX (Vulnerability Exploitability eXchange) to assert per-product whether a CVE is actually exploitable in their distribution.

SSVCAct

Active exploitation with total impact on essential/support systems

exploitation: active
automatable: yes
impact: total
mission: support

Lifecycle

2023-04-07Added to CISA KEVransomware: Known
2023-04-07Public exploit observedmetasploit
2023-04-07Published
2023-04-28Federal patch due (BOD 22-01)
2026-06-12Last modified1 source

No source-event history recorded yet. New revisions will appear here as ingestors re-fetch this CVE.