IRONSMITHINTEL
CRITICALCVSS9.4
|
Actively Exploited
|CISA KEV|CVE-2023-2868|Auth: none — unauthenticated|Reboot: required|Manual only

Barracuda Networks ESG Appliance Improper Input Validation Vulnerability

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

Published May 24, 2023 · Updated May 16, 2026
Why patchRisk explained in plain English
Worst-case scenarioIf unpatched

A remote attacker, without authentication, can achieve full data confidentiality loss, arbitrary modification of data, partial service disruption. Federal agencies are required to remediate by 2023-06-16 under CISA BOD 22-01.

How the attack worksNo clicks needed

This is a Improper Input Validation (CWE-20) vulnerability in Barracuda Networks Email Security Gateway (ESG) Appliance. 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. Exploitation requires remote network access, low attack complexity, no authentication required, and no user interaction required.

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Phishing link

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Malicious file

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Server compromised

Am I affected?Quick check

Probably yes if any of these apply:

IT Security
Running email security gateway 300 firmware: 5.1.3.001 ≤ v ≤ 9.2.0.006; email security gateway 400 firmware: 5.1.3.001 ≤ v ≤ 9.2.0.006; email security gateway 600 firmware: 5.1.3.001 ≤ v ≤ 9.2.0.006; email security gateway 800 firmware: 5.1.3.001 ≤ v ≤ 9.2.0.006; email security gateway 900 firmware: 5.1.3.001 ≤ v ≤ 9.2.0.006
Real-world incidentsWhat we've seen

CISA added this CVE to the Known Exploited Vulnerabilities catalog on 2023-05-26 based on evidence of active exploitation in the wild. Federal agencies required to remediate by 2023-06-16.

How to patch

Manual remediation steps

Apply the Vendor Patch

This vulnerability is in the CISA Known Exploited Vulnerabilities catalog — apply the vendor's security update as soon as possible.

CISA required action: Apply updates per vendor instructions.

References

    1
    Vendor advisory: https://status.barracuda.com/incidents/34kx82j5n4q9
    1
    NVD entry: https://nvd.nist.gov/vuln/detail/CVE-2023-2868
    1
    CISA KEV: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-2868
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