VYPR

CWE-646

Reliance on File Name or Extension of Externally-Supplied File

VariantIncompleteLikelihood: High

Description

The product allows a file to be uploaded, but it relies on the file name or extension of the file to determine the appropriate behaviors. This could be used by attackers to cause the file to be misclassified and processed in a dangerous fashion.

An application might use the file name or extension of a user-supplied file to determine the proper course of action, such as selecting the correct process to which control should be passed, deciding what data should be made available, or what resources should be allocated. If the attacker can cause the code to misclassify the supplied file, then the wrong action could occur. For example, an attacker could supply a file that ends in a ".php.gif" extension that appears to be a GIF image, but would be processed as PHP code. In extreme cases, code execution is possible, but the attacker could also cause exhaustion of resources, denial of service, exposure of debug or system data (including application source code), or being bound to a particular server side process. This weakness may be due to a vulnerability in any of the technologies used by the web and application servers, due to misconfiguration, or resultant from another flaw in the application itself.

Hierarchy (View 1000)

Parents

Children

none

Related attack patterns (CAPEC)

CAPEC-209

CVEs mapped to this weakness (5)

  • CVE-2026-45315HigMay 15, 2026
    risk 0.50cvss 8.7epss 0.00

    Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.3, the audio transcription upload endpoint takes the file extension from the user-supplied filename and saves the file under CACHE_DIR/audio/transcriptions/.. The…

  • CVE-2025-58449HigSep 8, 2025
    risk 0.50cvss epss 0.00

    Maho is a free and open source ecommerce platform. In Maho prior to 25.9.0, an authenticated staff user with access to the `Dashboard` and `Catalog\Manage Products` permissions can create a custom option on a listing with a file input field. By allowing file uploads with a…

  • CVE-2026-20172MedMay 6, 2026
    risk 0.28cvss 4.3epss 0.00

    A vulnerability in the Lite Agent feature of Cisco Enterprise Chat and Email (ECE) could allow an authenticated, remote attacker to conduct browser-based attacks. To exploit this vulnerability, the attacker must have valid credentials for a user account with at least the role of…

  • CVE-2025-41720MedOct 22, 2025
    risk 0.28cvss 4.3epss 0.00

    A low privileged remote attacker can upload arbitrary data masked as a png file to the affected device using the webserver API because only the file extension is verified.

  • CVE-2025-1889Mar 3, 2025
    risk 0.00cvss epss 0.00

    picklescan before 0.0.22 only considers standard pickle file extensions in the scope for its vulnerability scan. An attacker could craft a malicious model that uses Pickle and include a malicious pickle file with a non-standard file extension. Because the malicious pickle file…