Remote code execution in Barracuda Email Security Gateway Appliance (ESG)

1) Exposed dangerous method or function

EUVDB-ID: #VU84794

Risk: Critical

CVSSv3.1: 9.4 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:H/RL:O/RC:C]

CVE-ID: CVE-2023-7102

CWE-ID: CWE-749 - Exposed Dangerous Method or Function

Exploit availability: No

Description

The vulnerability allows a remote attacker to compromise the affected system.

The vulnerability exists due to improper input validation within the third-party Perl library Spreadsheet::ParseExcel used to parse Excel files. A remote attacker can send a specially crafted email with a malicious file inside and execute arbitrary code on the device.

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

Mitigation

On December 22, 2023, Barracuda deployed a patch to remediate compromised ESG appliances which exhibited indicators of compromise related to the newly identified malware variants.

Vulnerable software versions

Email Security Gateway (ESG): 5.1.3 - 9.2.1.001

CPE2.3

• cpe:2.3:a:barracuda_networks:esg:5.1.3:*:*:*:*:*:*:
• cpe:2.3:a:barracuda_networks:esg:5.1.3.003:*:*:*:*:*:*:
• cpe:2.3:a:barracuda_networks:esg:5.1.3.004:*:*:*:*:*:*:

External links

http://www.barracuda.com/company/legal/esg-vulnerability
http://www.cve.org/CVERecord?id=CVE-2023-7101
http://metacpan.org/dist/Spreadsheet-ParseExcel
http://github.com/haile01/perl_spreadsheet_excel_rce_poc
http://github.com/jmcnamara/spreadsheet-parseexcel/blob/c7298592e102a375d43150cd002feed806557c15/lib/Spreadsheet/ParseExcel/Utility.pm#L171
http://github.com/mandiant/Vulnerability-Disclosures/blob/master/2023/MNDT-2023-0019.md

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

Yes. This vulnerability is being exploited in the wild.