What it is
CVE-2021-27878 is a vulnerability affecting Veritas Backup Exec. An issue was discovered in Veritas Backup Exec before 21.2. The communication between a client and an Agent requires successful authentication, which is...
Vulnerability report
Exploited in the wild
Confirmed confidence
In CISA KEV
CVE-2021-27878
Backup Exec
Veritas / Backup Exec
- Severity
- CVSS 8.8 · High
- Confidence
- Confirmed
- Exploit status
- Exploited in the wild
- EPSS
- 24.0%
- First observed
- —
- Last observed
- —
Decision summary
What security teams need to know first
Direct answers before the deeper technical record.
Is it exploited?
Yes. KEV Intelligence tracks this CVE as a known exploited vulnerability. Confidence is confirmed.
Who is affected?
Veritas / Backup Exec.
What should we do?
Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
Overview
An issue was discovered in Veritas Backup Exec before 21.2
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. The attacker could use one of these commands to execute an arbitrary command on the system using system privileges.
- Published
- 01 Mar 2021
- Exploitation Reported
- 07 Apr 2023
- Attack vector
- Remote
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
Tags
ransomware
metasploit
cisa
malware
CVE References
- CVE Record CVE.org · CVE Record https://www.cve.org/CVERecord?id=CVE-2021-27878
- veritas.com/content/support/en_US/security/VTS21-001 veritas.com · CVE Record https://www.veritas.com/content/support/en_US/security/VTS21-001#issue3
- packetstormsecurity.com/files/168506/Veritas-Backup-Exec-Agent-Remot... packetstormsecurity.com · CVE Record http://packetstormsecurity.com/files/168506/Veritas-Backup-Exec-Agent...
Exploitation evidence
Why KEV Intelligence marks this CVE as exploited
Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.
Exploited in the wild
CISA
Independent exploitation attestation added to the KEV Intelligence record.
Used in malware
CISA
Malware families have been linked to exploitation of this CVE.
Proof of concept available
Public scanner or PoC coverage increases practical exploitability.
Known exploited vulnerability sources
Per-source evidence links for KEV attestations are available through the KEV Intelligence Pro API.
Learn about Pro API access| Source | Added |
|---|---|
| CISA First | 2023-04-07 00:00 UTC |
Detection
Operational artifacts and observed signals
Make the evidence actionable in scanner, SOC, and edge-control workflows.
Observed signals
- Request targets
- 0
- User-Agents
- 0
Raw values available in Pro and Enterprise.
Scanner coverage
Metasploit template detected 28 Apr 2025.
View Metasploit template (opens in new tab)Virtual patch status
No KEV Intelligence virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.
Learn about virtual patches →Scanner Artifacts
Scanner and exploit-framework references linked to this CVE.
| Scanner | Reference | Detected |
|---|---|---|
| Metasploit | https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/multi/veritas/beagent_sha_auth_rce.rb | 28 Apr 2025 |
Risk and context
Severity, weaknesses, and research context
CVSS v3.1
8.8
High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS
24.0%
All CVSS Scores
CVSS v3.1
8.8
High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS v2.0
9.0
High
AV:N/AC:L/Au:S/C:C/I:C/A:C
Potential Proof of Concepts
These PoCs are unverified and could contain malware. Use at your own risk.
Timeline
From disclosure to observed exploitation
-
Metasploit module available
Exploit module available
-
Public PoC available
Public proof-of-concept code published
-
Added to CISA KEV
Listed in the CISA Known Exploited Vulnerabilities catalog
-
First public exploitation report
Exploit observed in malware
-
CVE published
Vulnerability disclosed publicly
-
CVE ID reserved
Identifier reserved by the CNA
Pro API
Automate this intelligence
Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.
- Evidence confidence and provenance
- First-party sensor telemetry
- PoC and scanner references
- Affected versions and enrichment
- Automation-ready JSON delivery
GET /api/v2/pro/kevs/CVE-2021-27878
Free JSON includes basic KEV fields{
"cve_id": "CVE-2021-27878",
"confidence": "Confirmed",
"cvss_score": 8.8,
"cvss_estimated": false,
"epss_score": 0.23952,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": false
},
"sensor_telemetry": { "attempts": 0, "sensors": 0 }
}Early warning alerts
Get alerts on high-impact exploitation
Receive curator-selected alerts when exploitation activity warrants attention. Each alert includes the evidence and context needed to decide what requires attention now.