Intel

AIKIDO-2025-10587

Altinn.App.Api is vulnerable to Generation of Error Message Containing Sensitive Information

Generation of Error Message Containing Sensitive Information Pre-CVE
Found by Aikido Intel before public disclosure or CVE publication.
Published Aug 27, 2025

20

Low Risk

This Affects:

dotnetAltinn.App.Api
7.2.0 - 8.7.0
Fixed in 8.7.1
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TL;DR

Affected versions of this package are vulnerable to improper input validation in the handling of malformed Content-Disposition filenames. When an invalid or unquoted filename is supplied, the server responds with an internal error (HTTP 500) instead of a client error (HTTP 400). This behavior can inadvertently leak internal details or implementation-specific error messages to an attacker, increasing the risk of information disclosure. The patch fixes this by validating the header properly and returning a 400 Bad Request instead of a 500.

Who does this affect?

You are affected if you are using a version that falls within the vulnerable range.

Background info

Altinn.App.Api is vulnerable to Generation of Error Message Containing Sensitive Information in versions 7.2.0 - 8.7.0.

How to fix this

Upgrade the Altinn.App.Api library to the patch version.