CVE-2021-27646

CriticalCVSS 9.8/10Last modified Jun 17, 2026

Description

Use After Free vulnerability in iscsi_snapshot_comm_core in Synology DiskStation Manager (DSM) before 6.2.3-25426-3 allows remote attackers to execute arbitrary code via crafted web requests.

Metrics

CVSS 3.1 9.8/10CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Weakness enumeration

CWE-416

Affected software

Vendor	Product	Versions
Synology	Synology DiskStation Manager (DSM)	>= unspecified, < 6.2.3-25426-3

References

https://www.synology.com/security/advisory/Synology_SA_20_26Vendor Advisory
https://www.zerodayinitiative.com/advisories/ZDI-21-339/Not Applicable
https://www.zerodayinitiative.com/advisories/ZDI-21-340/Third Party Advisory, VDB Entry
https://www.synology.com/security/advisory/Synology_SA_20_26Vendor Advisory
https://www.zerodayinitiative.com/advisories/ZDI-21-339/Not Applicable
https://www.zerodayinitiative.com/advisories/ZDI-21-340/Third Party Advisory, VDB Entry

Timeline

Published: Mar 12, 2021
Last modified: Jun 17, 2026
NVD status: Modified

Related CVEs from 2021

CVE-2021-276479.8Out-of-bounds Read vulnerability in iscsi_snapshot_comm_core in Synology DiskStation Manager (DSM) before 6.2.3-25426-3 allows remote attack CVE-2021-276488.8Externally controlled reference to a resource in another sphere in quarantine functionality in Synology Antivirus Essential before 1.4.8-280 CVE-2021-276499.8Use after free vulnerability in file transfer protocol component in Synology DiskStation Manager (DSM) before 6.2.3-25426-3 allows remote at CVE-2021-276519.8In versions 8.2.1 through 8.5.2 of Pega Infinity, the password reset functionality for local accounts can be used to bypass local authentica CVE-2021-276534.9Misconfiguration of the Pega Chat Access Group portal in Pega platform 7.4.0 - 8.5.x could lead to unintended data exposure.CVE-2021-276547.8Forgotten password reset functionality for local accounts can be used to bypass local authentication checks.CVE-2021-276567.5A vulnerability in exacqVision Web Service 20.12.2.0 and prior could allow an unauthenticated attacker to view system-level information abou CVE-2021-276578.8Successful exploitation of this vulnerability could give an authenticated Metasys user an unintended level of access to the server file syst CVE-2021-276585.4exacqVision Enterprise Manager 20.12 does not sufficiently validate, filter, escape, and/or encode user-controllable input before it is plac CVE-2021-276596.1exacqVision Web Service 21.03 does not sufficiently validate, filter, escape, and/or encode user-controllable input before it is placed in o CVE-2021-276608.8An insecure client auto update feature in C-CURE 9000 can allow remote execution of lower privileged Windows programs.CVE-2021-276618.8Successful exploitation of this vulnerability could give an authenticated Facility Explorer SNC Series Supervisory Controller (F4-SNC) user