CVE-2021-29452
Any logged in user could edit any other logged in user.
a12n-server is an npm package which aims to provide a simple authentication system. A new HAL-Form was added to allow editing users in version 0.18.0. This feature should only have been accessible to admins. Unfortunately, privileges were incorrectly checked allowing any logged in user to make this change. Patched in v0.18.2.
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
- High
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Any logged in user could edit any other logged in user.
a12n-server is an npm package which aims to provide a simple authentication system. A new HAL-Form was added to allow editing users in version 0.18.0. This feature should only have been accessible to admins. Unfortunately, privileges were incorrectly checked allowing any logged in user to make this change. Patched in v0.18.2.
- Record
CVE-2021-29452- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-269
- Updated
- 2026-11-02
EUVDEUVD-2021-0800
a12n-server is an npm package which aims to provide a simple authentication system. A new HAL-Form was added to allow editing users in version 0.18.0. This feature should only have been accessible to admins. Unfortunately, privileges were incorrectly checked allowing any logged in user to make this change. Patched in v0.18.2.
- Record
EUVD-2021-0800- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-8hw9-22v6-9jr9
Any logged in user could edit any other logged in user.
Impact
Everyone who is running a12n-server.
A new HAL-Form was added to allow editing users. This feature should only have been accessible to admins. Unfortunately, privileges were incorrectly checked allowing any logged in user to make this change.
Patches
Patched in v0.18.2
- Record
GHSA-8hw9-22v6-9jr9- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-269, CWE-863
- Updated
- 2026-11-02
NVD
a12n-server is an npm package which aims to provide a simple authentication system. A new HAL-Form was added to allow editing users in version 0.18.0. This feature should only have been accessible to admins. Unfortunately, privileges were incorrectly checked allowing any logged in user to make this change. Patched in v0.18.2.
- Record
CVE-2021-29452- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N - CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N - CVSS 2.0
- 4.0 Medium
AV:N/AC:L/Au:S/C:N/I:P/A:N - Weakness
- CWE-269, CWE-863
- Updated
- 2026-11-02
OSV
a12n-server is an npm package which aims to provide a simple authentication system. A new HAL-Form was added to allow editing users in version 0.18.0. This feature should only have been accessible to admins. Unfortunately, privileges were incorrectly checked allowing any logged in user to make this change. Patched in v0.18.2.
- Record
CVE-2021-29452- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N - Updated
- 2026-11-02
OSVGHSA-8hw9-22v6-9jr9
Any logged in user could edit any other logged in user.
Impact
Everyone who is running a12n-server.
A new HAL-Form was added to allow editing users. This feature should only have been accessible to admins. Unfortunately, privileges were incorrectly checked allowing any logged in user to make this change.
Patches
Patched in v0.18.2
- Record
GHSA-8hw9-22v6-9jr9- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-269, CWE-863
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
@curveball/a12n-servernpm |
0.18.0 up to 0.18.2 | 0.18.2 |
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-2021-29452 is a high vulnerability (CVSS 8.1) in Curveball A12n-server, published April 16, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.78%, the 56th percentile. Fixed in @curveball/a12n-server 0.18.2.