Denial of service while parsing a tar file due to lack of folders count validation [MODERATE] [9] #210

New issue

Closed

opened 2024-04-16 19:15:23 +01:00 by Helpdesk · 0 comments

Helpdesk commented

2024-04-16 19:15:23 +01:00

Member

Package: tar (npm)
Affected versions: < 6.2.1
Patched version: 6.2.1

Description

During some analysis today on npm's node-tar package I came across the folder creation process, Basicly if you provide node-tar with a path like this ./a/b/c/foo.txt it would create every folder and sub-folder here a, b and c until it reaches the last folder to create foo.txt, In-this case I noticed that there's no validation at all on the amount of folders being created, that said we're actually able to CPU and memory consume the system running node-tar and even crash the nodejs client within few seconds of running it using a path with too many sub-folders inside

Steps To Reproduce

You can reproduce this issue by downloading the tar file I provided in the resources and using node-tar to extract it, you should get the same behavior as the video

Proof Of Concept

Here's a video show-casing the exploit:

Impact

Denial of service by crashing the nodejs client when attempting to parse a tar archive, make it run out of heap memory and consuming server CPU and memory resources

Note

This report was originally reported to GitHub bug bounty program, they asked me to report it to you a month ago

Package: tar (npm) Affected versions: < 6.2.1 Patched version: 6.2.1 --- ## Description During some analysis today on npm's `node-tar` package I came across the folder creation process, Basicly if you provide node-tar with a path like this `./a/b/c/foo.txt` it would create every folder and sub-folder here a, b and c until it reaches the last folder to create `foo.txt`, In-this case I noticed that there's no validation at all on the amount of folders being created, that said we're actually able to CPU and memory consume the system running node-tar and even crash the nodejs client within few seconds of running it using a path with too many sub-folders inside ## Steps To Reproduce You can reproduce this issue by downloading the tar file I provided in the resources and using node-tar to extract it, you should get the same behavior as the video ## Proof Of Concept Here's a [video](https://hackerone-us-west-2-production-attachments.s3.us-west-2.amazonaws.com/3i7uojw8s52psar6pg8zkdo4h9io?response-content-disposition=attachment%3B%20filename%3D%22tar-dos-poc.webm%22%3B%20filename%2A%3DUTF-8%27%27tar-dos-poc.webm&response-content-type=video%2Fwebm&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=ASIAQGK6FURQSWWGDXHA%2F20240312%2Fus-west-2%2Fs3%2Faws4_request&X-Amz-Date=20240312T080103Z&X-Amz-Expires=3600&X-Amz-Security-Token=IQoJb3JpZ2luX2VjEDcaCXVzLXdlc3QtMiJHMEUCID3xYDc6emXVPOg8iVR5dVk0u3gguTPIDJ0OIE%2BKxj17AiEAi%2BGiay1gGMWhH%2F031fvMYnSsa8U7CnpZpxvFAYqNRwgqsQUIQBADGgwwMTM2MTkyNzQ4NDkiDAaj6OgUL3gg4hhLLCqOBUUrOgWSqaK%2FmxN6nKRvB4Who3LIyzswFKm9LV94GiSVFP3zXYA480voCmAHTg7eBL7%2BrYgV2RtXbhF4aCFMCN3qu7GeXkIdH7xwVMi9zXHkekviSKZ%2FsZtVVjn7RFqOCKhJl%2FCoiLQJuDuju%2FtfdTGZbEbGsPgKHoILYbRp81K51zeRL21okjsOehmypkZzq%2BoGrXIX0ynPOKujxw27uqdF4T%2BF9ynodq01vGgwgVBEjHojc4OKOfr1oW5b%2FtGVV59%2BOBVI1hqIKHRG0Ed4SWmp%2BLd1hazGuZPvp52szmegnOj5qr3ubppnKL242bX%2FuAnQKzKK0HpwolqXjsuEeFeM85lxhqHV%2B1BJqaqSHHDa0HUMLZistMRshRlntuchcFQCR6HBa2c8PSnhpVC31zMzvYMfKsI12h4HB6l%2FudrmNrvmH4LmNpi4dZFcio21DzKj%2FRjWmxjH7l8egDyG%2FIgPMY6Ls4IiN7aR1jijYTrBCgPUUHets3BFvqLzHtPFnG3B7%2FYRPnhCLu%2FgzvKN3F8l38KqeTNMHJaxkuhCvEjpFB2SJbi2QZqZZbLj3xASqXoogzbsyPp0Tzp0tH7EKDhPA7H6wwiZukXfFhhlYzP8on9fO2Ajz%2F%2BTDkDjbfWw4KNJ0cFeDsGrUspqQZb5TAKlUge7iOZEc2TZ5uagatSy9Mg08E4nImBSE5QUHDc7Daya1gyqrETMDZBBUHH2RFkGA9qMpEtNrtJ9G%2BPedz%2FpPY1hh9OCp9Pg1BrX97l3SfVzlAMRfNibhywq6qnE35rVnZi%2BEQ1UgBjs9jD%2FQrW49%2FaD0oUDojVeuFFryzRnQxDbKtYgonRcItTvLT5Y0xaK9P0u6H1197%2FMk3XxmjD9%2Fb%2BvBjqxAQWWkKiIxpC1oHEWK9Jt8UdJ39xszDBGpBqjB6Tvt5ePAXSyX8np%2FrBi%2BAPx06O0%2Ba7pU4NmH800EVXxxhgfj9nMw3CeoUIdxorVKtU2Mxw%2FLaAiPgxPS4rqkt65NF7eQYfegcSYDTm2Z%2BHPbz9HfCaVZ28Zqeko6sR%2F29ML4bguqVvHAM4mWPLNDXH33mjG%2BuzLi8e1BF7tNveg2X9G%2FRdcMkojwKYbu6xN3M6aX2alQg%3D%3D&X-Amz-SignedHeaders=host&X-Amz-Signature=1e8235d885f1d61529b7d6b23ea3a0780c300c91d86e925dd8310d5b661ddbe2) show-casing the exploit: ## Impact Denial of service by crashing the nodejs client when attempting to parse a tar archive, make it run out of heap memory and consuming server CPU and memory resources ## Note This report was originally reported to GitHub bug bounty program, they asked me to report it to you a month ago