Multiple vulnerabilities in DrayTek Vigor3900, Vigor2960, and Vigor300B
| Risk | High |
| Patch available | YES |
| Number of vulnerabilities | 4 |
| CVE-ID | CVE-2020-14472 CVE-2020-14473 CVE-2020-14993 CVE-2020-15415 |
| CWE-ID | CWE-94 CWE-121 CWE-78 |
| Exploitation vector | Network |
| Public exploit | Public exploit code for vulnerability #3 is available. |
| Vulnerable software Subscribe |
Vigor 3900 Hardware solutions / Routers & switches, VoIP, GSM, etc Vigor 2960 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 4 vulnerabilities.
1) Code Injection
EUVDB-ID: #VU29334
Risk: High
CVSSv3.1: 8.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]
CVE-ID: CVE-2020-14472
CWE-ID:
CWE-94 - Improper Control of Generation of Code ('Code Injection')
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to improper input validation. A remote attacker can send a specially crafted request and execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
MitigationInstall updates from vendor's website.
Vulnerable software versionsVigor 3900: 1.4.4 _ - 1.5.1
Vigor 2960: 1.3.1 _ - 1.5.1
Vigor 300B: 1.3.3 _ - 1.5.1
External linksQ & 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.
2) Stack-based buffer overflow
EUVDB-ID: #VU29335
Risk: High
CVSSv3.1: 8.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]
CVE-ID: CVE-2020-14473
CWE-ID:
CWE-121 - Stack-based buffer overflow
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to a boundary error. A remote unauthenticated attacker can trigger a stack-based buffer overflow and execute arbitrary code on the target system or perform a denial of service (DoS) attack.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
MitigationInstall updates from vendor's website.
Vulnerable software versionsVigor 3900: 1.4.4 _ - 1.5.1
Vigor 2960: 1.3.1 _ - 1.5.1
Vigor 300B: 1.3.3 _ - 1.5.1
External linksQ & 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.
3) Stack-based buffer overflow
EUVDB-ID: #VU29336
Risk: High
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-2020-14993
CWE-ID:
CWE-121 - Stack-based buffer overflow
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to a boundary error when processing data passed via the formuserphonenumber parameter in an authusersms action to mainfunction.cgi . A remote non-authenticated user can send a specially crafted request to the affected device, trigger a stack-based buffer overflow and execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
PoC:
curl -d "action=authusersms&custom1=1;&custom2=1&custom3=1&formuserphonenumber=aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\xEC\xC7\x01&URL=www.baidu.com&HOST=123456897&serverip=";ls;echo 'pwn it';&filename=pwn" -X POST http://192.168.0.250/cgi-bin/mainfunciton.cgiInstall update from vendor's website.
Vulnerable software versionsVigor 3900: 1.4.4 _ - 1.5.1
Vigor 2960: 1.3.1 _ - 1.5.1
Vigor 300B: 1.3.3 _ - 1.5.1
External linkshttp://github.com/dexterone/Vigor-poc
http://www.draytek.com/about/security-advisory/vigor3900-/-vigor2960-/-vigor300b-stack-based-buffer-overflow-vulnerability-(cve-2020-14473)
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.
4) OS Command Injection
EUVDB-ID: #VU72386
Risk: High
CVSSv3.1: 8.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]
CVE-ID: CVE-2020-15415
CWE-ID:
CWE-78 - Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to execute arbitrary shell commands on the target system.
The vulnerability exists due to improper input validation within the "cgi-bin/mainfunction.cgi/cvmcfgupload" script. A remote unauthenticated attacker can send specially crafted HTTP request to the device and execute arbitrary OS commands on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
MitigationInstall updates from vendor's website.
Vulnerable software versionsVigor 2960: before 1.5.1.1
Vigor 3900: before 1.5.1.1
Vigor 300B: before 1.5.1.1
External linkshttp://github.com/CLP-team/Vigor-Commond-Injection
http://www.draytek.com/about/security-advisory/vigor3900-/-vigor2960-/-vigor300b-remote-code-injection/execution-vulnerability-(cve-2020-14472)/
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?
No. We are not aware of malware exploiting this vulnerability.
