CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
AI Score
Confidence
High
EPSS
Percentile
14.1%
A Denial-of-Service was found in the media upload process causing the server to crash without restarting, affecting either development and production environments.
Usually, errors in the application cause it to log the error and keep it running for other clients. This behavior, in contrast, stops the server execution, making it unavailable for any clients until it’s manually restarted.
Due to a bug in what we believe to be Burp’s decoding system, we couldn’t produce a valid file to easily reproduce the vulnerability. Instead, the issue can be reproduced by following these steps:
%00
at the end of the file extension from the Content-Disposition
, in the filename parameter (See reference image 1 below)%00
and right-click it. Click in Convert selection > URL > URL decode to transform the selected text into a null byteERR_INVALID_ARG_VALUE
(See reference log 1 below)By following the data flow, we reached the line of code where we believe the DoS is being caused.
The simpler way of fixing this vulnerability seems to be avoiding the error thrown by whitelisting the characters used in the extension.
[2024-03-22 10:23:42.629] http: POST /upload (22 ms) 400
node:internal/fs/utils:379
const err = new ERR_INVALID_ARG_VALUE(
^
TypeError [ERR_INVALID_ARG_VALUE]: The argument 'path' must be a string, Uint8Array, or URL without null bytes. Received '/mnt/storage/Development/GHSA-pm9q-xj9p-96pm/public/uploads/replaceme_png_88efe6a165.png\x00'
at new WriteStream (node:internal/fs/streams:340:5)
at Object.createWriteStream (node:fs:3123:10)
at /mnt/storage/Development/GHSA-pm9q-xj9p-96pm/node_modules/@strapi/provider-upload-local/dist/index.js:71:33
at new Promise (<anonymous>)
at Object.uploadStream (/mnt/storage/Development/GHSA-pm9q-xj9p-96pm/node_modules/@strapi/provider-upload-local/dist/index.js:68:16)
at Object.uploadStream (/mnt/storage/Development/GHSA-pm9q-xj9p-96pm/node_modules/@strapi/plugin-upload/server/register.js:80:35)
at Object.upload (/mnt/storage/Development/GHSA-pm9q-xj9p-96pm/node_modules/@strapi/plugin-upload/server/services/provider.js:16:46)
at Object.uploadImage (/mnt/storage/Development/GHSA-pm9q-xj9p-96pm/node_modules/@strapi/plugin-upload/server/services/upload.js:220:48) {
code: 'ERR_INVALID_ARG_VALUE'
}
Denial-of-Service occurs when a service becomes unavailable for users or other services.
By sending a specially-crafted request, the server crashes without restarting. The entire server crashes with the thrown error instead of crashing only the single request and returning error 500 to the user.
Any user with access to the file upload functionality is able to exploit this vulnerability, affecting applications running in both development mode and production mode as well.
Vendor | Product | Version | CPE |
---|---|---|---|
strapi | plugin-upload | * | cpe:2.3:a:strapi:plugin-upload:*:*:*:*:*:*:*:* |