What’s Vulnerable › Vulnerabilities

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

• Severity: medium (CVSS 5.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.8% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2020-01-09 · updated 2026-06-17
• Weakness: CWE-384

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.

Affected products

• pow-auth pow: before 1.0.16 — fixed in 1.0.16

How to fix

Upgrade to a fixed version: pow-auth pow 1.0.16. Check the vendor advisory for mitigations.

References

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

Get alerted when CVE-2020-5205 or the next vulnerability affects your stack