CVE-2019-16764
PowAssent is susceptible to denial of service attacks
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
PowAssent is susceptible to denial of service attacks
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.
- Record
CVE-2019-16764- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-400
- Updated
- 2026-11-02
EUVDEUVD-2022-1629
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.
- Record
EUVD-2022-1629- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-5653-437f-5hmc
Denial of service
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.
- Record
GHSA-5653-437f-5hmc- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-400
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2019-16764- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - CVSS 3.1
- 5.5 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - CVSS 2.0
- 2.1 Low
AV:L/AC:L/Au:N/C:N/I:N/A:P - Weakness
- CWE-400
- Updated
- 2026-11-02
OSV
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.
- Record
CVE-2019-16764- CVSS 3.1
- 5.5 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVGHSA-5653-437f-5hmc
Denial of service
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.
- Record
GHSA-5653-437f-5hmc- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-400
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
pow_assentHex |
before 0.4.4 | 0.4.4 |
pow_assentHex |
before 0.4.4, plus listed versions 0.1.00.1.0-alpha0.1.0-alpha.10.1.0-alpha.100.1.0-alpha.11 Show 24 moreShow less0.1.0-alpha.120.1.0-alpha.20.1.0-alpha.30.1.0-alpha.40.1.0-alpha.50.1.0-alpha.60.1.0-alpha.70.1.0-alpha.80.1.0-alpha.90.1.0-rc.00.1.0-rc.10.1.0-rc.20.2.00.2.10.2.20.2.30.2.40.3.00.3.10.3.20.4.00.4.10.4.20.4.3 |
0.4.4 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2019-16764 is a medium vulnerability (CVSS 6.5) in Powauth Powassent, published November 25, 2019. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.08%, the 65th percentile. Fixed in pow_assent 0.4.4.
References
github.com/pow-auth/pow_assent/security/advisories/GHSA-368c-xvrv-x986
hex.pm/packages/pow_assent
erlang.org/doc/efficiency_guide/commoncaveats.html
nvd.nist.gov/vuln/detail/CVE-2019-16764