Privilege escalation in Synology NAS Servers

1) Privilege escalation

EUVDB-ID: #VU1062

Risk: Low

CVSSv4.0: 8.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2016-6554

CWE-ID: CWE-255 - Credentials Management

Exploit availability: No

Description

The vulnerability allows a remote unauthenticated user to bypass security limitations and gain elevated privileges on the target system.
The weakness exists due to improper protection of credentials. By accessing the server with default credentials, attacker can bypass security limitations and increase his privileges.
Successful exploitation of the vulnerability results in privilege escalation and full access to the vulnerable system.

Mitigation

Update to version 5.2-5644 -1.

Vulnerable software versions

Synology NAS Servers: 3.1 - 5.2-5644-1

CPE2.3

• cpe:2.3:h:synology:synology_nas_servers:3.1:*:*:*:*:*:*:*
• cpe:2.3:h:synology:synology_nas_servers:3.1-1639:*:*:*:*:*:*:*
• cpe:2.3:h:synology:synology_nas_servers:4.0:*:*:*:*:*:*:*

External links

http://www.kb.cert.org/vuls/id/404187

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.