1. Summary

Vulnerability Name

Apache Johnzon Deserialization of Untrusted Data Vulnerability (CVE-2023-33008)

Release Date

July 13, 2023

Component Name

Apache Johnzon

Affected Versions

Apache Johnzon < 1.2.21

Vulnerability Type

CWE-502: Deserialization of Untrusted Data

Severity

CVSS v3 Base Score: 5.3 (Medium)

Exploitability

Attack Vector: Network

Attack Complexity: Low

Privileges Required: None

User Interaction: None

Impact

Confidentiality Impact: None

Integrity Impact: None

Availability Impact: Low

2. About the Vulnerability CVE-2023-33008

2.1 Introduction

Apache Johnzon is a lightweight Java library used for parsing and generating JSON (JavaScript Object Notation) data.

2.2 Summary

On July 13, 2023, Sangfor FarSight Labs detected a deserialization of untrusted data vulnerability in the Apache Johnzon, identified as CVE-2023-33008, with a severity rating of Medium (CVSS Score 5.3).

The vulnerability arises because Apache Johnzon does not perform adequate checks on input data during the deserialization process. A malicious attacker can exploit the vulnerability by crafting JSON input that contains large numbers (e.g., 1e20000000). When Apache Johnzon attempts to deserialize this input, it interprets the large number as a BigDecimal and may trigger the conversion to a BigInteger using BigDecimal#toBigInteger().

The conversion from BigDecimal to BigInteger can be very slow, especially when dealing with extremely large BigDecimal numbers. The attacker can leverage this slow conversion by sending a significant amount of JSON data containing such large numbers to force Apache Johnzon to repeatedly perform the slow BigDecimal#toBigInteger() conversion. This resource-intensive operation can put a strain on the system's processing capabilities, potentially leading to a Denial of Service (DoS) risk.

3. Affected Versions

Apache Johnzon < 1.2.21

4. Solutions

4.1 Apache Solution

4.1.1 Version Upgrade

Apache has released a new version of Johnzon to fix the vulnerability. Users are recommended to upgrade to the latest version.

Link: https://johnzon.apache.org/download.html

5. Timeline

On July 13, 2023, Sangfor FarSight Labs received a notice about the Apache Johnzon Denial of Service Vulnerability (CVE-2023-33008).

On July 13, 2023, Sangfor FarSight Labs released a vulnerability alert.

6. Reference

https://issues.apache.org/jira/browse/JOHNZON-397

https://nvd.nist.gov/vuln/detail/CVE-2023-33008

7. Learn More

Sangfor FarSight Labs researches the latest cyberthreats and unknown zero-day vulnerabilities, alerting customers to potential dangers to their organizations, and providing real-time solutions with actionable intelligence. Sangfor FarSight Labs works with other security vendors and the security community at large to identify and verify global cyberthreats, providing fast and easy protection for customers.

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