CVE-2019-16764
PowAssent is susceptible to denial of service attacks
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
Description
The use of `String.to_atom/1` in PowAssent is susceptible to denial of service attacks. In `PowAssent.Phoenix.AuthorizationController` a value is fetched from the user provided params, and `String.to_atom/1` is used to convert the binary value to an atom so it can be used to fetch the provider configuration value. This is unsafe as it is user provided data, and can be used to fill up the whole atom table of ~1M which will cause the app to crash.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Medium6.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
| NVDNVD · Modified | 3.1 | Medium5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 1.1% · top 35% of all CVEs (6 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.5.
Weakness
Affected products
- affected < 0.4.4 – < 0.4.4
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- Hexpow_assentGHSA-5653-437f-5hmc (opens in a new tab)
What to do
Workaround: A plug can be used to validate conn.params["provider"] before it reaches the PowAssent.Phoenix.AuthorizationController.
References (4)
- https://github.com/pow-auth/pow_assent/security/advisories/GHSA-368c-xvrv-x986 (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://hex.pm/packages/pow_assent (opens in a new tab)x_refsource_MISCx_transferred
- http://erlang.org/doc/efficiency_guide/commoncaveats.html#list_to_atom-1 (opens in a new tab)x_refsource_MISCx_transferred
- https://github.com/pow-auth/pow_assent/commit/026105eeecc0e3c2f807e7109e745ea93c0fd9cf (opens in a new tab)x_refsource_MISCx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-5653-437f-5hmc (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2019-16764)Record last updated .