CVE-2018-1000125

CRITICAL

inversoft prime-jwt <1.3.0 - Info Disclosure

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 2 public exploits for CVE-2018-1000125. PoCs published by dawetmaster, andikahilmy.

AI-analyzed exploit summary This repository contains a vulnerable version of the Prime JWT library (1.2.1) that demonstrates CVE-2018-1000125, an authentication bypass vulnerability due to improper handling of the 'none' algorithm in JWT verification. The code includes functional JWT encoding/decoding logic, including support for HMAC and RSA signing, but lacks proper validation for unsecured tokens.

Description

inversoft prime-jwt version prior to version 1.3.0 or prior to commit 0d94dcef0133d699f21d217e922564adbb83a227 contains an input validation vulnerability in JWTDecoder.decode that can result in a JWT that is decoded and thus implicitly validated even if it lacks a valid signature. This attack appear to be exploitable via an attacker crafting a token with a valid header and body and then requests it to be validated. This vulnerability appears to have been fixed in 1.3.0 and later or after commit 0d94dcef0133d699f21d217e922564adbb83a227.

Exploits (2)

nomisec WORKING POC
by dawetmaster · poc
https://github.com/dawetmaster/CVE-2018-1000125-prime-jwt-vulnerable

This repository contains a vulnerable version of the Prime JWT library (1.2.1) that demonstrates CVE-2018-1000125, an authentication bypass vulnerability due to improper handling of the 'none' algorithm in JWT verification. The code includes functional JWT encoding/decoding logic, including support for HMAC and RSA signing, but lacks proper validation for unsecured tokens.

Classification
Working Poc 90%
Attack Type
Auth Bypass
Complexity
Trivial
Reliability
Reliable
Target: Prime JWT 1.2.1
No auth needed
Prerequisites: A vulnerable version of Prime JWT (1.2.1)
devstral-2 · analyzed Mar 14, 2026 Full analysis →
nomisec WORKING POC
by andikahilmy · poc
https://github.com/andikahilmy/CVE-2018-1000125-prime-jwt-vulnerable

This repository contains a vulnerable version of the Prime JWT library (1.2.1) that demonstrates CVE-2018-1000125, an authentication bypass vulnerability due to improper handling of the 'none' algorithm in JWT verification. The code includes functional JWT encoding/decoding logic, including support for HMAC and RSA signing, but lacks proper validation for unsecured tokens.

Classification
Working Poc 90%
Attack Type
Auth Bypass
Complexity
Trivial
Reliability
Reliable
Target: Prime JWT 1.2.1
No auth needed
Prerequisites: Access to a system using Prime JWT 1.2.1 for JWT verification
devstral-2 · analyzed Feb 18, 2026 Full analysis →

References (2)

Core 2
Core References
Release Notes, Third Party Advisory x_refsource_confirm
https://github.com/inversoft/prime-jwt/blob/master/CHANGES
Third Party Advisory x_refsource_confirm
https://github.com/inversoft/prime-jwt/issues/2

Scores

CVSS v3 9.8
EPSS 0.0141
EPSS Percentile 69.2%
Attack Vector NETWORK
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Details

CWE
CWE-20
Status published
Products (1)
inversoft/prime-jwt < 1.3.0
Published Mar 13, 2018
Tracked Since Feb 18, 2026