Description

A flaw has been found in Insta InstaKNXServiceApp 1.2.3.1469. Affected by this issue is the function CreateWebClientAndDownloadFileList of the component Firmware Update Handler. Executing a manipulation can lead to insufficient verification of data authenticity. It is possible to launch the attack remotely. Attacks of this nature are highly complex. The exploitation is known to be difficult. The vendor was contacted early about this disclosure but did not respond in any way.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "3.7",
  "pubDate": "2026-08-06T22:16:53.253Z",
  "pubdate": "2026-08-06T22:16:53.253Z",
  "executiveSummary": "A vulnerability categorized as insufficient verification of data authenticity has been identified in Insta InstaKNXServiceApp version 1.2.3.1469. This security flaw resides within the Firmware Update Handler component, specifically within the function CreateWebClientAndDownloadFileList. The vulnerability allows remote threat actors to initiate attacks over the network, potentially leading to unauthorized manipulation of downloaded files and update processes.\nAlthough the attack vector is remote, exploitation of this vulnerability is characterized by high complexity and recognized as difficult to execute successfully. The risk implications include the potential compromise of firmware integrity if an attacker successfully intercepts or manipulates the data retrieval process due to the lack of adequate authenticity checks. The vendor was contacted early about this disclosure but did not respond in any way, and no official vendor patches are documented as available at this time.",
  "technicalDetails": "The vulnerability exists within the Insta InstaKNXServiceApp software, specifically affecting version 1.2.3.1469. The root cause of the security issue stems from the Firmware Update Handler component, where the function CreateWebClientAndDownloadFileList fails to sufficiently verify the authenticity of data retrieved during the update or file list downloading process. Insufficient verification of data authenticity means that the application accepts and processes downloaded files or file lists without cryptographically validating their origin, integrity, or authenticity against a trusted baseline.\nThe affected function, CreateWebClientAndDownloadFileList, is exposed to remote network access, allowing an external entity to interact with the service over the network. Because the application does not properly authenticate the source or ensure the integrity of the downloaded content, an attacker capable of performing remote interactions or network-based manipulations can influence the execution flow. The attack flow typically involves the adversary leveraging the network exposure to interact with the Firmware Update Handler, prompting the vulnerable function to execute a data retrieval operation under conditions where authenticity is insufficiently verified.\nWhile exploitation is known to be difficult and of high complexity, successful exploitation allows remote payloads or malicious file lists to be processed by the application. This lack of verification can lead to unauthorized data handling, potentially facilitating further downstream exploitation depending on how the downloaded file list is subsequently parsed and utilized by the system. Authentication and privilege requirements are dictated by the underlying service implementation, but the attack vector is explicitly noted as remote. Post-exploitation impact revolves around the compromised integrity of the firmware update mechanism, which could theoretically allow unauthorized data ingestion into the target environment."
}