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

Vulnerability summary

CVE-2023-2868 is a critical (CVSS 9.8) Improper Input Validation vulnerability in Barracuda Networks Email Security Gateway (ESG) Appliance. It is known to be exploited: CISA lists it, first on 26-05-2023. EPSS estimates a 86.84% chance of exploitation in the next 30 days, higher than 99.7% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 24-05-2023
   PublishedVulnerability first disclosed.
2. 26-05-2023
   Added to CISA KEVExploitedBarracuda Networks ESG Appliance Improper Input Validation Vulnerability
3. 16-06-2023
   CISA remediation dueDeadline passedApply updates per vendor instructions.
4. 21-10-2025
   Last modifiedVulnerability information updated.

Description

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.

• CWE-20Improper Input ValidationThe product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
• CWE-77Improper Neutralization of Special Elements used in a Command ('Command Injection')The product constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component.