CVE-2020-14798: Oracle OpenJDK Auth Bypass Vulnerability

CVE-2020-14798 Overview

CVE-2020-14798 is a vulnerability in the Java SE and Java SE Embedded products from Oracle Java SE, specifically affecting the Libraries component. This vulnerability allows an unauthenticated attacker with network access via multiple protocols to compromise Java SE and Java SE Embedded deployments. The vulnerability is difficult to exploit and requires human interaction from a person other than the attacker. Successful exploitation can result in unauthorized update, insert, or delete access to some accessible data within Java SE and Java SE Embedded environments.

This vulnerability specifically applies to Java deployments running sandboxed Java Web Start applications or sandboxed Java applets that load and run untrusted code (e.g., code from the internet) and rely on the Java sandbox for security. Server-side Java deployments that only load and run trusted code (e.g., administrator-installed code) are not affected by this vulnerability.

Critical Impact

Successful exploitation allows unauthorized modification of data in client-side Java deployments running untrusted code, potentially compromising data integrity in sandboxed Java applications.

Affected Products

• Oracle JDK 1.7.0 Update 271, 1.8.0 Update 261, 11.0.8, and 15
• Oracle JRE 1.7.0 Update 271, 1.8.0 Update 261, 11.0.8, and 15
• Oracle OpenJDK 7 (through Update 271), 8 (through Update 262), 11.0.8, 13.0.4, and 15
• Java SE Embedded 8u261
• NetApp products including Active IQ Unified Manager, E-Series SANtricity products, OnCommand Insight, SnapManager, SolidFire, and HCI Management/Storage Nodes
• Debian Linux 9.0 and 10.0
• openSUSE Leap 15.2

Discovery Timeline

• October 21, 2020 - CVE-2020-14798 published to NVD
• May 27, 2025 - Last updated in NVD database

Technical Details for CVE-2020-14798

Vulnerability Analysis

The vulnerability resides within the Libraries component of Oracle Java SE and Java SE Embedded. This component is fundamental to Java's core functionality, providing essential classes and utilities used throughout Java applications. The flaw enables an attacker to perform unauthorized data modifications, though the attack vector requires specific conditions to be successful.

The exploitation complexity is high due to several constraining factors. The attacker must have network access to the target system and the attack requires human interaction—meaning a user must perform some action (such as visiting a malicious website or opening a malicious file) for the exploit to succeed. Additionally, the scope is unchanged, meaning the vulnerable component and impacted component are the same.

Root Cause

The vulnerability stems from improper handling within the Java Libraries component. While Oracle has not disclosed specific technical details about the root cause (classified as NVD-CWE-noinfo), the vulnerability affects the integrity of data accessible by Java applications. The flaw manifests when sandboxed Java applications process untrusted content, allowing potential bypass of security controls designed to prevent unauthorized data modification.

Attack Vector

The attack is network-based, meaning an attacker can exploit this vulnerability remotely without requiring physical access to the target system. The exploitation scenario typically involves:

1. An attacker crafts malicious content designed to exploit the vulnerability in the Libraries component
2. The attacker delivers this content via a network vector (web page, email attachment, etc.)
3. A user running a vulnerable Java version interacts with the malicious content
4. The sandboxed Java application processes the untrusted code
5. The vulnerability is triggered, allowing unauthorized data modification

The vulnerability specifically targets client-side Java deployments such as Java Web Start applications and Java applets that execute untrusted code while relying on the Java sandbox for security isolation.

Detection Methods for CVE-2020-14798

Indicators of Compromise

• Unexpected modifications to data within Java application contexts without authorized user actions
• Suspicious network connections from Java processes to untrusted external endpoints
• Java applet or Web Start application execution from untrusted sources
• Anomalous behavior in sandboxed Java environments indicating potential sandbox escape attempts

Detection Strategies

• Monitor for execution of Java Web Start (javaws) and applet-related processes from untrusted sources
• Implement application control policies to detect unauthorized Java version executions
• Deploy network monitoring to identify suspicious traffic patterns originating from Java processes
• Review Java deployment logs for indicators of untrusted code execution attempts

Monitoring Recommendations

• Establish baseline behavior for Java applications and alert on deviations in data access patterns
• Configure SentinelOne agents to monitor Java process behaviors and flag suspicious activity
• Enable audit logging for Java application data access and modifications
• Implement real-time alerting for Java sandbox bypass attempts or integrity violations

How to Mitigate CVE-2020-14798

Immediate Actions Required

• Update all affected Java installations to the latest patched versions available from Oracle
• Disable Java browser plugins if not required for business operations
• Restrict execution of Java Web Start applications and applets from untrusted sources
• Review and enforce Java security settings to limit execution of untrusted code

Patch Information

Oracle addressed this vulnerability in the October 2020 Critical Patch Update. Organizations should upgrade to the following minimum versions or later:

• Java SE 7u281 or later
• Java SE 8u271 or later
• Java SE 11.0.9 or later
• Java SE 15.0.1 or later

Additional security advisories and patches are available from:

• Debian Security Advisory DSA-4779
• NetApp Security Advisory
• Gentoo GLSA 202101-19
• openSUSE Security Announcement

Workarounds

• Disable Java Web Start and Java applet functionality in browsers if not required for business functions
• Configure Java security settings to prevent execution of unsigned or untrusted applets
• Implement network segmentation to isolate systems running legacy Java applications that cannot be immediately updated
• Deploy SentinelOne endpoint protection to detect and block exploitation attempts targeting Java vulnerabilities

# Disable Java plugin in browsers (Windows example)
# Navigate to Java Control Panel > Security tab
# Uncheck "Enable Java content in the browser"

# Alternatively, remove Java plugin registration
reg delete "HKLM\SOFTWARE\MozillaPlugins\@java.com/JavaPlugin" /f
reg delete "HKLM\SOFTWARE\MozillaPlugins\@java.com/JavaPlugin,version=11.0.8" /f