CVE-2020-14577: Oracle OpenJDK Information Disclosure Flaw

CVE-2020-14577 Overview

CVE-2020-14577 is an information disclosure vulnerability in the Java Secure Socket Extension (JSSE) component of Oracle Java SE and Java SE Embedded. This vulnerability allows an unauthenticated attacker with network access via TLS to potentially read a subset of sensitive data from affected Java deployments. The vulnerability affects both client and server deployments and can be exploited through sandboxed Java Web Start applications, sandboxed Java applets, or by supplying malicious data to JSSE APIs through web services.

Critical Impact

Successful exploitation enables unauthorized read access to sensitive data transmitted over TLS connections in Java applications, potentially exposing confidential information processed by the JSSE component.

Affected Products

• Oracle OpenJDK 7u261, 8u251, 11.0.7, 13.0.3, and 14
• Oracle JDK 1.7.0 Update 261, 1.8.0 Update 251, 11.0.7, and 14.0.1
• Oracle JRE 1.7.0 Update 261, 1.8.0 Update 251, 11.0.7, and 14.0.1
• Java SE Embedded 8u251
• Fedora 31 and 32
• Canonical Ubuntu Linux 16.04 ESM, 18.04 LTS, and 20.04 LTS
• openSUSE Leap 15.1 and 15.2
• Debian Linux 9.0 and 11.0
• NetApp products including Active IQ Unified Manager, Cloud Backup, OnCommand Insight, StorageGRID, and others

Discovery Timeline

• July 15, 2020 - CVE-2020-14577 published to NVD
• May 27, 2025 - Last updated in NVD database

Technical Details for CVE-2020-14577

Vulnerability Analysis

This vulnerability resides in the JSSE (Java Secure Socket Extension) component, which provides the framework and implementation for SSL/TLS protocols in Java. The flaw allows an unauthenticated remote attacker to gain unauthorized read access to a subset of data accessible by the affected Java SE and Java SE Embedded products.

The vulnerability requires network access via TLS to exploit, meaning attackers must be able to establish TLS connections with the target system. While exploitation is considered difficult due to the complexity required to successfully trigger the information disclosure, no user interaction or special privileges are needed. The impact is limited to confidentiality—there are no integrity or availability impacts associated with this vulnerability.

Root Cause

The root cause stems from improper handling within the JSSE component during TLS communication processing. The specific implementation flaw allows certain data to be exposed to unauthorized parties when specific conditions are met during the TLS handshake or data transmission phases. Oracle has not disclosed detailed technical specifics about the exact code path that enables this information leakage.

Attack Vector

The attack can be conducted remotely over the network via TLS connections. There are multiple exploitation paths available to attackers:

1. Java Web Start Applications - Exploitation through sandboxed Java Web Start applications that interact with the JSSE component
2. Java Applets - Through sandboxed Java applets running in web browsers
3. Web Services - By supplying crafted data to JSSE APIs without requiring sandboxed applications, such as through malicious web service requests

The vulnerability primarily manifests during TLS communication where the attacker can position themselves to intercept or extract information due to the JSSE implementation flaw. The attack complexity is high, as specific timing or conditions must be met for successful exploitation.

Detection Methods for CVE-2020-14577

Indicators of Compromise

• Unusual TLS connection patterns or malformed TLS handshake attempts targeting Java applications
• Anomalous network traffic to Java-based services that handle sensitive data over TLS
• Unexpected data extraction attempts from Java web services or applications

Detection Strategies

• Monitor network traffic for suspicious TLS connection patterns to Java application servers
• Implement deep packet inspection for TLS connections to identify potential exploitation attempts
• Review Java application logs for unusual JSSE-related errors or exceptions during TLS processing
• Deploy SentinelOne agents to detect anomalous behavior in Java processes

Monitoring Recommendations

• Enable verbose logging for Java applications using JSSE for TLS communications
• Implement network-level monitoring for TLS connections to critical Java services
• Configure alerts for repeated failed or anomalous TLS handshake attempts
• Audit Java application endpoints that process external data through JSSE APIs

How to Mitigate CVE-2020-14577

Immediate Actions Required

• Update all affected Oracle Java SE installations to the latest patched versions immediately
• Apply security updates from your Linux distribution (Fedora, Ubuntu, Debian, openSUSE) for OpenJDK packages
• Review and update any NetApp products that include affected Java versions
• Conduct an inventory of all Java applications using JSSE for TLS communications

Patch Information

Oracle released security patches addressing this vulnerability as part of the Oracle Critical Patch Update for July 2020. Organizations should upgrade to the following minimum versions:

• Java SE 7u271 or later
• Java SE 8u261 or later
• Java SE 11.0.8 or later
• Java SE 14.0.2 or later

Additional security advisories and patches are available from:

• Debian Security Advisory DSA-4734
• Ubuntu Security Notice USN-4433-1
• Ubuntu Security Notice USN-4453-1
• NetApp Security Advisory
• Gentoo GLSA 202209-15

Workarounds

• Restrict network access to Java-based services to trusted networks and clients only
• Implement network segmentation to limit exposure of Java applications handling sensitive data
• Consider disabling Java Web Start and Java applets if not required for business operations
• Apply additional network-level protections such as WAF rules for web services using JSSE

# Verify installed Java version and check for vulnerability
java -version

# For Linux systems, update OpenJDK packages
# Debian/Ubuntu:
sudo apt update && sudo apt upgrade openjdk-11-jdk

# Fedora:
sudo dnf update java-11-openjdk

# Verify the patch level after update
java -XshowSettings:all 2>&1 | grep "java.version"