CVE-2023-2868: Barracuda Networks ESG Appliance Improper Input Validation Vulnerability

Is it exploited?

Yes. CISA added it to the Known Exploited Vulnerabilities catalog on 26 May 2023, 2 days after the CVE record was published.

How likely is exploitation in the next 30 days?

86.8%

EPSS score, percentile 99.7 of all scored records

How severe?

9.4 Critical

CVSS v3.1 base score, given by the CNA

What should I do?

CISA deadline 16 Jun 2023. Apply updates per vendor instructions.

The CVE record links no vendor advisory, patch or mitigation.

Which versions are affected?

Affected

• from 5.1.3.001 to before 9.2.0.006

Versions by product

Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.

What to do

CISA due date for this action: 16 June 2023.

Advisories and patches

The CVE record links no vendor advisory, patch or mitigation.

Linked from CISA's catalog entry

• https://status.barracuda.com/incidents/34kx82j5n4q9
• https://nvd.nist.gov/vuln/detail/CVE-2023-2868

Affected products and versions

As listed in the CVE record.

Versions not listed are: unaffected.

Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.

About this vulnerability

Barracuda Email Security Gateway (ESG) appliance contains an improper input validation vulnerability of a user-supplied .tar file, leading to remote command injection.

Summary: CISA's KEV catalog, as of 28 Oct 2026.

• CISA added CVE-2023-2868 to its Known Exploited Vulnerabilities (KEV) catalog on 26 May 2023.
• CISA's ransomware flag for this entry is "Unknown": no evidence of ransomware use in the catalog, which is not proof of none.
• The due date CISA sets for the required action is 16 Jun 2023.
• The CVE record was published on 24 May 2023, 2 days before it was added to KEV.
• The CVE record carries a CVSS v3.1 base score of 9.4 (Critical), given by its CNA.
• FIRST's EPSS model puts the probability of exploitation in the next 30 days at 86.8% (percentile 99.7), as of 28 Oct 2026.
• CISA's SSVC assessment in the CVE record: exploitation active, automatable yes, technical impact total.

Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026. About the data.

Description

Remote Code injection in Barracuda Email Security Gateway

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.

Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.

Weakness

• CWE-20: Improper Input Validation

Attack patterns (CAPEC)

• CAPEC-253: Remote Code Inclusion

CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record and the KEV entry.

Timeline

References

• barracuda.com
• status.barracuda.com