CVE-2019-16764 — The use of `String

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 fetc

01What is this vulnerability?

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…

02Affected products

Vendor	Product	Versions
pow-auth	pow_assent	< 0.4.4

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2019-11-25T17:11:19.000Z
• Last modified: 2024-08-05T01:24:47.215Z

09References

• github.com — https://github.com/pow-auth/pow_assent/security/advisories/GHSA-368c-xvrv-x986
• hex.pm — https://hex.pm/packages/pow_assent
• erlang.org — http://erlang.org/doc/efficiency_guide/commoncaveats.html#list_to_atom-1
• github.com — https://github.com/pow-auth/pow_assent/commit/026105eeecc0e3c2f807e7109e745ea93c…