CVE-2021-27964
SonLogger before 6.4.1 is affected by Unauthenticated Arbitrary File Upload. An attacker can send...
SonLogger before 6.4.1 is affected by Unauthenticated Arbitrary File Upload. An attacker can send a POST request to /Config/SaveUploadedHotspotLogoFile without any authentication or session header. There is no check for the file extension or content of the uploaded file.
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
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
SonLogger before 6.4.1 is affected by Unauthenticated Arbitrary File Upload. An attacker can send a POST request to /Config/SaveUploadedHotspotLogoFile without any authentication or session header. There is no check for the file extension or content of the uploaded file.
- Record
CVE-2021-27964- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 7.5 High
AV:N/AC:L/Au:N/C:P/I:P/A:P - Weakness
- CWE-434
- Updated
- 2026-11-02
CVE List No score
SonLogger before 6.4.1 is affected by Unauthenticated Arbitrary File Upload. An attacker can send a POST request to /Config/SaveUploadedHotspotLogoFile without any authentication or session header. There is no check for the file extension or content of the uploaded file.
- Record
CVE-2021-27964- Updated
- 2026-11-02
EUVDEUVD-2021-14682 No score
SonLogger before 6.4.1 is affected by Unauthenticated Arbitrary File Upload. An attacker can send a POST request to /Config/SaveUploadedHotspotLogoFile without any authentication or session header. There is no check for the file extension or content of the uploaded file.
- Record
EUVD-2021-14682- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-mxm8-cmpq-g5cx No score
SonLogger before 6.4.1 is affected by Unauthenticated Arbitrary File Upload. An attacker can send...
SonLogger before 6.4.1 is affected by Unauthenticated Arbitrary File Upload. An attacker can send a POST request to /Config/SaveUploadedHotspotLogoFile without any authentication or session header. There is no check for the file extension or content of the uploaded file.
- Record
GHSA-mxm8-cmpq-g5cx- Weakness
- CWE-434
- Updated
- 2026-11-02
Affected products
Public exploits
Links only. Every CVE stores no exploit code.
| Source | Link | Date |
|---|---|---|
| Exploit-DB | SonLogger 4.2.3.3 - Unauthenticated Arbitrary File Upload (Metasploit) | 2021-03-15 |
| Nuclei | SonLogger - Arbitrary File Upload |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, Exploit-DB, GitHub Advisories, Nuclei, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-27964 is a critical vulnerability (CVSS 9.8) in Sfcyazilim Sonlogger, published March 5, 2021. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 47.5%, the 98th percentile. No source names a fixed version.