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Weekly Signal
Live intelligence Updated 19 Aug 2026 · 13:41 UTC

Barracuda, Barracuda Networks · Email Security Gateway 300 Firmware, Email Security Gateway 400 Firmware, Email Security Gateway 600 Firmware +3 more

CVE-2023-2868

Barracuda Networks ESG Appliance Improper Input Validation Vulnerability

Recommended action

Validate affected assets and exposure now, then remediate on an accelerated schedule. Apply updates per vendor instructions.

View response plan
CVSS9.8
EPSS87.4%
KEVYes
ExploitationConfirmed exploitation
PatchPatch or guidance available ↓

Assessment

Why it matters

CISA lists this vulnerability as known to be exploited; exploitation is confirmed; EPSS is 87.4%; technical severity is CVSS 9.8.

A remote command injection vulnerability exists in the Barracuda Email Security Gateway (appliance form factor only) product effecting versions 5.1.3.001-9.2.0.006. The vulnerability arises out of a failure to comprehensively sanitize the processing of .tar file (tape archives). The vulnerability stems from incomplete input validation of a user-supplied .tar file as it pertains to the names of the files contained within the archive. As a consequence, a remote attacker can specifically format these file names in a particular manner that will result in remotely executing a system command through Perl's qx operator with the privileges of the Email Security Gateway product. This issue was fixed as part of BNSF-36456 patch. This patch was automatically applied to all customer appliances.

Who should care

  • Teams operating Email Security Gateway 300 Firmware, Email Security Gateway 400 Firmware, Email Security Gateway 600 Firmware +3 more
  • Vulnerability and exposure management teams
  • Security operations teams monitoring exploitation activity

Response plan

What I would do

  1. Confirm whether Email Security Gateway 300 Firmware, Email Security Gateway 400 Firmware, Email Security Gateway 600 Firmware +3 more is present in the environment.
  2. Identify affected versions and establish whether vulnerable services are exposed or reachable.
  3. Apply updates per vendor instructions.
  4. Review relevant security telemetry for evidence of attempted or successful exploitation.
  5. Document the remediation decision and track it to verified completion.

Vendor remediation

Patch and remediation links

Use the vendor source below to confirm the correct fixed version, package or mitigation for your affected product.

Technical details

CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE
CWE-20
Affected versions
Barracuda Email Security Gateway 300 Firmware (Start Including: 5.1.3.001, End Including: 9.2.0.006); Barracuda Email Security Gateway 400 Firmware (Start Including: 5.1.3.001, End Including: 9.2.0.006); Barracuda Email Security Gateway 600 Firmware (Start Including: 5.1.3.001, End Including: 9.2.0.006); Barracuda Email Security Gateway 800 Firmware (Start Including: 5.1.3.001, End Including: 9.2.0.006); Barracuda Email Security Gateway 900 Firmware (Start Including: 5.1.3.001, End Including: 9.2.0.006); Barracuda Networks Email Security Gateway (ESG) Appliance
Published
24 May 2023
Attack vector
Network
Privileges required
None
User interaction
None

Signal timeline

  1. CVE published
  2. Added to CISA KEV
  3. Latest EPSS score: 87.4%
  4. Signal calculated at 84

External references

Live public intelligence This assessment combines public-source evidence. Validate the affected product, version and exposure against your own environment before making a risk decision.