Vulnerability identifier: #VU52354

Vulnerability risk: High

CVSSv3.1: 7.2 [CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-26566

CWE-ID: CWE-77

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
DiskStation Manager (DSM)
Server applications / File servers (FTP/HTTP)

Vendor: Synology Inc.

Description

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

The vulnerability exists due to insertion of sensitive information into sent data issue in synorelayd. A remote attacker can perform a man-in-the-middle attack to execute arbitrary commands via inbound QuickConnect traffic.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

DiskStation Manager (DSM): 6.2.3 25426-2

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External links
http://www.synology.com/security/advisory/Synology_SA_20_26
http://www.talosintelligence.com/vulnerability_reports/TALOS-2020-1160

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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.