CVE-2021-27963
SonLogger before 6.4.1 is affected by user creation with any user permissions profile (e.g.,...
SonLogger before 6.4.1 is affected by user creation with any user permissions profile (e.g., SuperAdmin). An anonymous user can send a POST request to /User/saveUser without any authentication or session header.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
SonLogger before 6.4.1 is affected by user creation with any user permissions profile (e.g., SuperAdmin). An anonymous user can send a POST request to /User/saveUser without any authentication or session header.
- Record
CVE-2021-27963- CVSS 3.1
- 8.2 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N - CVSS 2.0
- 6.4 Medium
AV:N/AC:L/Au:N/C:P/I:P/A:N - Weakness
- CWE-306
- Updated
- 2026-11-02
CVE List No score
SonLogger before 6.4.1 is affected by user creation with any user permissions profile (e.g., SuperAdmin). An anonymous user can send a POST request to /User/saveUser without any authentication or session header.
- Record
CVE-2021-27963- Updated
- 2026-11-02
EUVDEUVD-2021-14681 No score
SonLogger before 6.4.1 is affected by user creation with any user permissions profile (e.g., SuperAdmin). An anonymous user can send a POST request to /User/saveUser without any authentication or session header.
- Record
EUVD-2021-14681- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-qjp9-v762-692g
SonLogger before 6.4.1 is affected by user creation with any user permissions profile (e.g.,...
SonLogger before 6.4.1 is affected by user creation with any user permissions profile (e.g., SuperAdmin). An anonymous user can send a POST request to /User/saveUser without any authentication or session header.
- Record
GHSA-qjp9-v762-692g- CVSS 3.1
- 8.2 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N - Weakness
- CWE-732
- Updated
- 2026-11-02
Affected products
Public exploits
Links only. Every CVE stores no exploit code.
| Source | Link | Date |
|---|---|---|
| PoC in GitHub | erberkan/SonLogger-vulns | 2021-02-26 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, PoC in GitHub |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-27963 is a high vulnerability (CVSS 8.2) in Sfcyazilim Sonlogger, published March 5, 2021. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 2.45%, the 84th percentile. No source names a fixed version.