Zero-day vulnerability in Vigor 2960

Improper Neutralization of Special Elements in Output Used by a Downstream Component
CVE-2020-8515

The vulnerability in WebUI of DrayTek Vigor enterprise routers is being exploited in the wild at least from December 4, 2019. Two affected scripts are believed to be used by two different attack groups to eavesdrop on FTP and email traffic inside corporate networks.

Vulnerability details

Advisory: SB2020021407 - Remote code execution in Draytek Vigor 2960, 3900 and 300B

Vulnerable component: Vigor 2960

CVE-ID: CVE-2020-8515

CVSSv3 score: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:H/RL:O/RC:C

CWE-ID: CWE-74 - Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')

Description:

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

The vulnerability exists due to the affected devices allow remote code execution as root (without authentication) via shell metacharacters to the "cgi-bin/mainfunction.cgi" URI.

Note, this vulnerability is being actively exploited in the wild starting from December 4, 2019.