CVE-2021-27647
Out-of-bounds Read 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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (3.25%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Out-of-bounds Read 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.
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 3.25% probability · 88th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-125
- Affected
- synology/diskstation manager
- Source
- security@synology.com
EPSS 3.2% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://www.synology.com/security/advisory/Synology_SA_20_26Vendor Advisory
- https://www.zerodayinitiative.com/advisories/ZDI-21-339/Third Party Advisory, VDB Entry
- https://www.synology.com/security/advisory/Synology_SA_20_26Vendor Advisory
- https://www.zerodayinitiative.com/advisories/ZDI-21-339/Third Party Advisory, VDB Entry
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.