CVE-2023-2868
Barracuda Networks ESG Appliance Improper Input Validation Vulnerability
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 status
CISA Known Exploited Vulnerabilities
Listed by CISA on 26 May 2023. US federal agencies were required to remediate it by 16 June 2023.
EPSS — exploitation probability
FIRST puts the probability of exploitation activity in the next 30 days at 86.8%, which is higher than 99.7% of all scored vulnerabilities. EPSS is a forecast of activity, not a measure of severity, and it is rescored daily.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L
Frequently asked questions
Is CVE-2023-2868 being exploited by ransomware groups?
No ransomware group in this database is currently recorded as exploiting CVE-2023-2868.
What does CVE-2023-2868 affect?
CVE-2023-2868 affects 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.
How severe is CVE-2023-2868?
CVE-2023-2868 is rated CRITICAL with a CVSS base score of 9.4. EPSS puts the probability of exploitation in the next 30 days at 86.8%, higher than 99.7% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 16 June 2023.
How should organisations respond to CVE-2023-2868?
Apply the vendor patch for Barracuda Networks Email Security Gateway (ESG) Appliance as the first priority, and treat any internet-facing instance as the most urgent. Because this vulnerability is associated with ransomware activity, also review whether the affected systems were reachable before patching, rather than assuming that patching alone closes the incident.