Vulnerability identifier: #VU52350

Vulnerability risk: High

CVSSv3.1: 7.8 [CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-26562

CWE-ID: CWE-787

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 compromise vulnerable system.

The vulnerability exists due to a boundary error when processing "syno_finder_site" HTTP header. A remote attacker can perform a man-in-the-middle attack, trigger out-of-bounds write and execute arbitrary code on the target system.

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-2020-1159

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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.