PT-2021-17175 · Discord · Probot

Published

2021-02-09

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Updated

2024-08-03

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CVE-2021-26918

CVSS v3.1

9.8

Critical

VectorAV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Name of the Vulnerable Software and Affected Versions: ProBot bot through 2021-02-08 for Discord
Description: The issue allows attackers to interfere with the intended purpose of the "Send an image when a user joins the server" feature, or possibly have unspecified other impact, because the uploader web service allows double extensions (such as .html.jpg) with the text/html content type. The nature of the issue has substantial interaction with customer-controlled configuration.
Recommendations: For ProBot bot through 2021-02-08, consider restricting the file types accepted by the uploader web service to prevent double extensions, such as .html.jpg, from being uploaded with the text/html content type. As a temporary workaround, consider disabling the "Send an image when a user joins the server" feature until a more robust solution is available.

Exploit

Fix

Unrestricted File Upload

Weakness Enumeration

CWE-434

Related Identifiers

CVE-2021-26918

Affected Products

Probot