CVE-2019-9845: MadsKristensen.AspNetCore.Miniblog subject to Improper Input Validation
9.8
CVSS Score
3.0
Basic Information
CVE ID
GHSA ID
EPSS Score
0.74129%
CWE
Published
7/5/2019
Updated
1/11/2023
KEV Status
No
Technology
C#
Technical Details
CVSS Vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Package Name | Ecosystem | Vulnerable Versions | First Patched Version |
---|---|---|---|
MadsKristensen.AspNetCore.Miniblog | nuget | <= 1.0.3 |
Vulnerability Intelligence
Miggo AI
Root Cause Analysis
The vulnerability description explicitly identifies SaveFilesToDisk
in BlogController.cs
as the source of improper input validation. The function decodes()
base64 data and writes it to disk using a filename
derived from user-controlled input (the 'data-filename' attribute). While the current GitHub code shows an allowed extensions
check, the vulnerability exists in versions <=1.0.3 where this validation was either absent or insufficient. Attackers could bypass checks by manipulating the filename
extension, enabling ASPX
file uploads. The link to CVE-2019-9845
and the exploit analysis confirms this mechanism.