Description

lestrrat-go/jwx's malicious parameters in JWE can cause a DOS

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"
)...
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Impact

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

Mitigation

Aliases

References