CVE-2021-31684

HIGH

json-smart-v1 1.3-1.3.2 and 2.4-2.4.3 - Denial of Service via JSONParserByteArray indexOf Function

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 2 public exploits for CVE-2021-31684. PoCs published by dawetmaster, andikahilmy.

AI-analyzed exploit summary This repository contains the vulnerable source code of json-smart-v2, specifically highlighting the ASMUtil.java file and related components. It provides a technical overview of the library's structure and mentions CVE-2021-27568 in the changelog, but does not include an exploit PoC or detailed analysis of CVE-2021-31684.

Description

A vulnerability was discovered in the indexOf function of JSONParserByteArray in JSON Smart versions 1.3 and 2.4 which causes a denial of service (DOS) via a crafted web request.

Exploits (2)

nomisec WRITEUP
by dawetmaster · poc
https://github.com/dawetmaster/CVE-2021-31684-json-smart-v2-vulnerable

This repository contains the vulnerable source code of json-smart-v2, specifically highlighting the ASMUtil.java file and related components. It provides a technical overview of the library's structure and mentions CVE-2021-27568 in the changelog, but does not include an exploit PoC or detailed analysis of CVE-2021-31684.

Classification
Writeup 90%
Attack Type
Other
Complexity
Moderate
Reliability
Theoretical
Target: json-smart-v2
No auth needed
Prerequisites: None
devstral-2 · analyzed Mar 14, 2026 Full analysis →
nomisec WRITEUP
by andikahilmy · poc
https://github.com/andikahilmy/CVE-2021-31684-json-smart-v2-vulnerable

This repository contains the vulnerable source code of json-smart-v2, specifically highlighting CVE-2021-31684. The README provides a detailed changelog and background but lacks explicit exploit code or technical deep-dive into the vulnerability itself.

Classification
Writeup 90%
Attack Type
Deserialization
Complexity
Moderate
Reliability
Theoretical
Target: json-smart-v2 (versions prior to fix)
No auth needed
Prerequisites: Access to an application using vulnerable json-smart-v2 for JSON parsing
devstral-2 · analyzed Feb 18, 2026 Full analysis →

Scores

CVSS v3 7.5
EPSS 0.0011
EPSS Percentile 28.8%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-787
Status published
Products (6)
json-smart_project/json-smart-v1 1.3 - 1.3.3
json-smart_project/json-smart-v2 2.4 - 2.4.4
net.minidev/json-smart 1.3.0 - 1.3.3Maven
oracle/utilities_framework 4.4.0.0.0
oracle/utilities_framework 4.4.0.2.0
oracle/utilities_framework 4.4.0.3.0
Published Jun 01, 2021
Tracked Since Feb 18, 2026