Security readout for executives and security teams
CVE-2021-27877 lets an unauthenticated remote attacker abuse a legacy SHA authentication scheme in Veritas Backup Exec before 21.2 to access an Agent and run privileged commands. Because CISA lists it in KEV, treat exposed legacy deployments as already targeted in the wild. Organizations running Veritas Backup Exec before 21.2 are the relevant exposure. Risk is highest where Backup Exec Agents are reachable from untrusted networks or from compromised internal segments. High priority. This is an older backup-platform vulnerability with known exploitation and privileged command impact. Backup systems often hold sensitive data and recovery authority, so exposed legacy instances should be upgraded or isolated quickly. Mitigation focus: Identify all Veritas Backup Exec servers and Agents.; Upgrade affected deployments to Backup Exec 21.2 or later per Veritas guidance.; Restrict Agent network exposure to trusted management hosts only..
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
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ATT&CK lookup starting points
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CVE-2021-27877 mapping review
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Open ATT&CK lookup- Severity
- High
- CVSS
- 8.2 (3.1)
- Known Exploited
- Yes
- Published
Vector: CVSS:3.1/AC:L/AV:N/A:N/C:H/I:L/PR:N/S:U/UI:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CISA KEV status
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AC:L/AV:N/A:N/C:H/I:L/PR:N/S:U/UI:N3.94.2Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.2HighVector: CVSS:3.1/AC:L/AV:N/A:N/C:H/I:L/PR:N/S:U/UI:N
Source materials
- CVE List V5 sourceCVE List V5
- https://www.veritas.com/content/support/en_US/security/VTS21-001#issue1CVE reference · x_refsource_MISC
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-27877CVE reference · government-resource
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.