Multiple vulnerabilities in Buffalo routers
| Risk | Critical |
| Patch available | NO |
| Number of vulnerabilities | 3 |
| CVE-ID | CVE-2021-20090 CVE-2021-20091 CVE-2021-20092 |
| CWE-ID | CWE-22 CWE-94 CWE-284 |
| Exploitation vector | Network |
| Public exploit | Vulnerability #1 is being exploited in the wild. |
| Vulnerable software Subscribe |
WSR-2533DHPL2 Hardware solutions / Routers & switches, VoIP, GSM, etc WSR-2533DHP3 Hardware solutions / Routers & switches, VoIP, GSM, etc |
| Vendor | BUFFALO INC. |
Security Bulletin
This security bulletin contains information about 3 vulnerabilities.
Updated: 25.08.2021
Updated description for vulnerability #VU52635, raised bulletin risk level from High to Critical to reflect in-the-wild exploitation.
1) Path traversal
EUVDB-ID: #VU52635
Risk: Critical
CVSSv3.1: 9.8 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:H/RL:U/RC:C]
CVE-ID: CVE-2021-20090
CWE-ID:
CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to perform directory traversal attacks.
The vulnerability exists due to input validation error when processing directory traversal sequences in the web interfaces. A remote attacker can send a specially crafted HTTP request and bypass authentication.
Note, the vulnerability is being exploited in-the-wild by the Mirai botnet in August 2021.
Cybersecurity Help is currently unaware of any official solution to address this vulnerability.
Vulnerable software versionsWSR-2533DHPL2: 1.02
WSR-2533DHP3: 1.24
External linkshttp://www.tenable.com/security/research/tra-2021-13
http://medium.com/tenable-techblog/bypassing-authentication-on-arcadyan-routers-with-cve-2021-20090-and-rooting-some-buffalo-ea1dd30980c2
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?
Yes. This vulnerability is being exploited in the wild.
2) Code Injection
EUVDB-ID: #VU52637
Risk: Medium
CVSSv3.1: 6.9 [CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:U/RC:C]
CVE-ID: CVE-2021-20091
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 in the web interfaces. A remote authenticated 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.
MitigationCybersecurity Help is currently unaware of any official solution to address this vulnerability.
Vulnerable software versionsWSR-2533DHPL2: 1.02
WSR-2533DHP3: 1.24
External linkshttp://www.tenable.com/security/research/tra-2021-13
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote authenticated user 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) Improper access control
EUVDB-ID: #VU52638
Risk: Medium
CVSSv3.1: 5.4 [CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N/E:U/RL:U/RC:C]
CVE-ID: CVE-2021-20092
CWE-ID:
CWE-284 - Improper Access Control
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to gain unauthorized access to otherwise restricted functionality.
The vulnerability exists due to improper access restrictions in the web interfaces. A remote attacker can bypass implemented security restrictions and gain unauthorized access to sensitive information on the system.
MitigationCybersecurity Help is currently unaware of any official solution to address this vulnerability.
Vulnerable software versionsWSR-2533DHPL2: 1.02
WSR-2533DHP3: 1.24
External linkshttp://www.tenable.com/security/research/tra-2021-13
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.
