Secuno
ENNL
Book demo

CVE-2021-27876

Veritas Backup Exec Agent File Access

8.1 HIGHActively exploited (CISA KEV)Used in ransomwarePublic exploitEPSS 13.5%
  1. Published1 Mar 2021
  2. Added to CISA KEV7 Apr 2023
  3. Remediation due28 Apr 2023
Actively exploited (CISA KEV)

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.

Added to KEV: 7 Apr 2023Federal remediation due: 28 Apr 2023Used in ransomware

Description

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. By using crafted input parameters in one of these commands, an attacker can access an arbitrary file on the system using System privileges.

CVSS 3.1 breakdown

Attack vectorNetwork
Attack complexityLow
Privileges requiredLow
User interactionNone
ScopeUnchanged
ConfidentialityHigh
IntegrityHigh
AvailabilityNone
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

Affected products

Veritas Backup Exec< 21.2

Remediation

Fixed in
Veritas Backup Exec≥ 21.2

References

Frequently asked

Is CVE-2021-27876 being actively exploited?

Yes. CVE-2021-27876 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added 7 Apr 2023. It has been used in ransomware campaigns.

How severe is CVE-2021-27876?

CVE-2021-27876 has a CVSS 3.1 base score of 8.1, rated high. EPSS estimates a 13.5% probability of exploitation.

Which products are affected by CVE-2021-27876?

Affected products include Veritas Backup Exec.

How do I fix CVE-2021-27876?

Upgrade affected software to a fixed version, for example Veritas Backup Exec 21.2 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2021-27876 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. Because it is on the CISA KEV list, Secuno flags any affected asset as top-priority automatically. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

See how prioritisation worksBook a demo

Get Patch this first every Monday

Five vulnerabilities that matter this week, ranked on real exploitation. Plain language, one email, no spam.

You can unsubscribe with one click from every issue. We handle your details as described in our privacy policy.

Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.