CVE-2025-3519: Replace uploaded files knowing the file upload ID
Description
An authorization bypass in Unblu Spark allows a participant of a conversation to replace an existing, uploaded file.
Every uploaded file in Unblu gets assigned with a randomly generated Universally Unique ID (UUID). In case a participant of this or another conversation gets access to such a file ID, it can be used to replace the file without changing the file name and details or the name of the user who uploaded the file. During the upload, file interception and allowed file type rules are still applied correctly.
Classification
CVE ID: CVE-2025-3519
CVSS Base Severity: HIGH
CVSS Base Score: 7.0
CVSS Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:H/SA:N
Problem Types
CWE-639 Authorization Bypass Through User-Controlled KeyAffected Products
Vendor: Unblu inc.
Product: Unblu Spark
Exploit Prediction Scoring System (EPSS)
EPSS Score: 0.04% (probability of being exploited)
EPSS Percentile: 12.83% (scored less or equal to compared to others)
EPSS Date: 2025-05-21 (when was this score calculated)
References
https://nvd.nist.gov/vuln/detail/CVE-2025-3519https://www.unblu.com/en/docs/latest/security-bulletins/#UBL-2025-001