Remote code execution in Draytek Vigor 2960, 3900 and 300B
| Risk | Critical |
| Patch available | YES |
| Number of vulnerabilities | 1 |
| CVE-ID | CVE-2020-8515 |
| CWE-ID | CWE-74 |
| Exploitation vector | Network |
| Public exploit | This vulnerability is being exploited in the wild. |
| Vulnerable software |
Vigor 2960 Hardware solutions / Routers & switches, VoIP, GSM, etc Vigor 3900 Hardware solutions / Routers & switches, VoIP, GSM, etc Vigor 300B Hardware solutions / Routers & switches, VoIP, GSM, etc |
| Vendor | DrayTek Corp. |
Security Bulletin
This security bulletin contains information about 1 vulnerabilities.
Updated: 28.03.2020
Added information about in the wild vulnerability exploitation, raised severity level for this bulletin from high to critical, updated references section and CVSS score.
1) Improper Neutralization of Special Elements in Output Used by a Downstream Component
EUVDB-ID: #VU25350
Risk: Critical
CVSSv3.1: 8.8 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C]
CVE-ID: CVE-2020-8515
Exploit availability: Yes
DescriptionThe 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.
Install updates from vendor's website.
Vulnerable software versionsVigor 2960: 1.3.1 _
Vigor 3900: 1.4.4 _
Vigor 300B: 1.3.3 _ - 1.4.4 _
CPE2.3- cpe:2.3:h:draytek_corp:vigor_2960:1.3.1:_:*:*:*:*:*:
- cpe:2.3:h:draytek_corp:vigor_3900:1.4.4:_:*:*:*:*:*:
- cpe:2.3:h:draytek_corp:vigor_300b:1.3.3:_:*:*:*:*:*:
- cpe:2.3:h:draytek_corp:vigor_300b:1.4.2.1:_:*:*:*:*:*:
- cpe:2.3:h:draytek_corp:vigor_300b:1.4.4:_:*:*:*:*:*:
http://sku11army.blogspot.com/2020/01/draytek-unauthenticated-rce-in-draytek.html
http://www.draytek.com/about/security-advisory/vigor3900-/-vigor2960-/-vigor300b-router-web-management-page-vulnerability-(cve-2020-8515)/
http://blog.netlab.360.com/two-zero-days-are-targeting-draytek-broadband-cpe-devices-en/
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
How the attacker can exploit this vulnerability?
The attacker would have to send a specially crafted request to the affected device in order to exploit this vulnerability.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.
