CVE-2021-27877
Confirmed PUBLISHEDAn issue was discovered in Veritas Backup Exec before 21.2. It supports multiple authentication schemes: SHA authentication is one of these. This...
Recommended Action
Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
At a Glance
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.
- CVE Published
- Mar 01, 2021
- Exploitation Reported
- Apr 07, 2023
- CVSS
- 8.2 High
- EPSS
- —
Affected Versions
| Vendor | Product | Version | Status |
|---|---|---|---|
| n/a |
n/a
|
n/a |
Affected |
CVE References
- veritas.com/content/support/en_US/security/VTS21-001 veritas.com · CVE Record https://www.veritas.com/content/support/en_US/security/VTS21-001#issue1
- packetstormsecurity.com/files/168506/Veritas-Backup-Exec-Agent-Remot... packetstormsecurity.com · CVE Record http://packetstormsecurity.com/files/168506/Veritas-Backup-Exec-Agent...
Recommended Actions
- Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
- Check enrichment artifacts for scanner coverage and available PoCs before rolling remediation validation.
- Use the Pro API to automate enrichment, telemetry, and workflow delivery for VM, SOC, and CTI pipelines.
Known Exploited Vulnerability Sources
Catalogues that list this CVE as a known exploited vulnerability.
Per-source evidence links for KEV attestations are available through the KEVIntel Pro API.
Learn about Pro API access| Source | Added |
|---|---|
| CISA First | 2023-04-07 00:00 UTC |
Scanner Artifacts
Nuclei and Metasploit references linked to this CVE.
| Scanner | Reference | Detected |
|---|---|---|
| Nuclei | https://github.com/projectdiscovery/nuclei-templates/blob/main/network/cves/2021/CVE-2021-27877.yaml | Jun 01, 2026 |
| Metasploit | https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/multi/veritas/beagent_sha_auth_rce.rb | Apr 28, 2025 |
Virtual Patch
Compensating WAF rules to help reduce exposure to this CVE. Rule content and deployable vendor exports are available with KEVIntel Enterprise.
KEVIntel does not currently have a virtual patch for this CVE. When available, KEVIntel virtual patches ship as deployable ModSecurity, Cloudflare, and AWS WAF rules.
Enterprise feature. Virtual patch rule content and deployable vendor exports (ModSecurity, Cloudflare, AWS WAF) are available to KEVIntel Enterprise users.
CVSS Scores
CVSS:3.1/AC:L/AV:N/A:N/C:H/I:L/PR:N/S:U/UI:N
Exploitation Status
Exploited in the wild
Recorded 2023-04-07 00:00:00 UTC · CISA
Used in malware
Recorded 2023-04-07 00:00:00 UTC · CISA
Proof of concept available
Recorded 2026-06-12 14:21:14 UTC · Nuclei Templates
Scanner Integrations
| Scanner | Reference | Detected |
|---|---|---|
| Nuclei | https://github.com/projectdiscovery/nuclei-templates/blob/main/network/cves/2021/CVE-2021-27877.yaml | Jun 01, 2026 |
| Metasploit | https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/multi/veritas/beagent_sha_auth_rce.rb | Apr 28, 2025 |
Potential Proof of Concepts
These PoCs are unverified and could contain malware. Use at your own risk.
nuclei · Created Unknown
Timeline
Key exploitation, disclosure, scanner coverage, and KEV attestation events for this CVE.
-
14:21 UTC about 1 month ago14:21 UTC · about 1 month ago
Public PoC available
Public proof-of-concept code published
-
15:34 UTC about 2 months ago15:34 UTC · about 2 months ago
Nuclei template available
Scanner coverage available
-
15:02 UTC about 1 year ago15:02 UTC · about 1 year ago
Metasploit module available
Exploit module available
-
00:00 UTC over 3 years ago00:00 UTC · over 3 years ago
Added to CISA KEV
Listed in the CISA Known Exploited Vulnerabilities catalog
-
00:00 UTC over 3 years ago00:00 UTC · over 3 years ago
First public exploitation report
Exploit observed in malware
-
21:49 UTC over 5 years ago21:49 UTC · over 5 years ago
CVE published
Vulnerability disclosed publicly
-
00:00 UTC over 5 years ago00:00 UTC · over 5 years ago
CVE ID reserved
Identifier reserved by the CNA
Automate This Intelligence with the Pro API
Confidence scoring, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.
Pro API Example
GET /api/v2/pro/kevs/CVE-2021-27877
{
"cve_id": "CVE-2021-27877",
"title": "An issue was discovered in Veritas Backup Exec before 21.2. It supports multi...",
"affected_vendor": "Veritas",
"affected_product": "Backup Exec",
"affected_versions": [
{ "vendor": "...", "product": "...", "status": "affected", "display_label": "..." }
],
"confidence": "Confirmed",
"cvss_score": 8.2,
"epss_score": null,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": false
},
"sensor_telemetry": { "...": "Pro API fields" },
"proof_of_concepts": [ "..." ],
"scanner_integrations": [ "..." ]
}