Zero-day vulnerability in Email Security Gateway (ESG)

OS Command Injection
CVE-2023-2868

Vulnerability details

Advisory: SB2023052509 - Remote code execution in Barracuda Email Security Gateway appliance (ESG)

Vulnerable component: Email Security Gateway (ESG)

CVE-ID: CVE-2023-2868

CVSSv3 score: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H/E:H/RL:O/RC:C

CWE-ID: CWE-78 - Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

Description:

The vulnerability allows a remote attacker to execute arbitrary shell commands on the target system.

The vulnerability exists due to improper input validation when processing .tar archives during email attachment screening. A remote unauthenticated attacker can send a specially crafted email with a malicious attachment to the appliance and execute arbitrary Perl commands on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Note, the vulnerability is being actively exploited in the wild.

External links:

https://www.barracuda.com/company/legal/esg-vulnerability

About zero-day vulnerabilities

Zero-day vulnerability is an undisclosed vulnerability in software that hackers can exploit to compromise computer programs, gain unauthorized access to sensitive data, penetrate networks, etc. We consider vulnerability a zero-day when there is no solution provided from software vendor and the vulnerability is being actively exploited by malicious actors.

Zero-day candidate is a potential zero-day vulnerability in software which might have been used in targeted attacks, however there is no evidence to support this suggestion.