CVE-2024-20919: Oracle GraalVM Auth Bypass Vulnerability

CVE-2024-20919 Overview

CVE-2024-20919 is an integrity-impacting vulnerability in the Hotspot component of Oracle Java SE, Oracle GraalVM for JDK, and Oracle GraalVM Enterprise Edition. An unauthenticated remote attacker can exploit the flaw over the network by supplying crafted data to APIs in the affected component. Successful exploitation enables unauthorized creation, modification, or deletion of data accessible to the Java runtime. Oracle addressed the issue in the January 2024 Critical Patch Update. The flaw does not require user interaction, but attack complexity is high, which limits opportunistic exploitation. Confidentiality and availability are not impacted; only integrity is affected.

Critical Impact

Unauthenticated attackers with network access can compromise the integrity of data processed by affected Java runtimes through specially crafted API input, without requiring credentials or user interaction.

Affected Products

• Oracle Java SE: 8u391, 8u391-perf, 11.0.21, 17.0.9, 21.0.1
• Oracle GraalVM for JDK: 17.0.9, 21.0.1
• Oracle GraalVM Enterprise Edition: 20.3.12, 21.3.8, 22.3.4

Discovery Timeline

• 2024-02-17 - CVE-2024-20919 published to NVD
• 2024-01 - Oracle releases fix in the January 2024 Critical Patch Update
• 2025-11-04 - Last updated in NVD database

Technical Details for CVE-2024-20919

Vulnerability Analysis

The vulnerability resides in the Hotspot virtual machine, the core execution engine of the Java Development Kit and GraalVM runtimes. Hotspot handles bytecode interpretation, just-in-time compilation, and memory management for all Java workloads. A defect in this component lets an unauthenticated attacker manipulate runtime data integrity by feeding malicious input to APIs exposed by hosted applications.

Exploitation requires network reachability to a service that processes attacker-controlled data through the vulnerable Hotspot code paths. Typical exposure surfaces include web services, RPC endpoints, and message handlers running on affected JDK versions. The vulnerability is not exploitable through Untrusted Java Web Start applications or Untrusted Java applets.

The impact is limited to integrity. Attackers cannot read sensitive data or crash the runtime, but they can alter records, configuration values, or business state processed by the application. The high attack complexity reflects conditions outside attacker control that must be present for the exploit chain to succeed.

Root Cause

The NVD entry maps this issue to NVD-CWE-noinfo, indicating Oracle did not publish a specific weakness category. The defect is internal to the Hotspot component shared across Java SE and GraalVM distributions.

Attack Vector

The attack proceeds over the network across multiple protocols. An attacker submits crafted data to an application API that routes the input into the vulnerable Hotspot code path. The vulnerability mechanism is not publicly detailed; refer to the Oracle Security Alert January 2024 for vendor-supplied technical context.

Detection Methods for CVE-2024-20919

Indicators of Compromise

• Unexpected modifications to application data or configuration originating from external API calls processed by Java services.
• Anomalous request payloads targeting endpoints backed by affected JDK or GraalVM versions.
• Java processes running versions 8u391, 11.0.21, 17.0.9, 21.0.1, or affected GraalVM builds without the January 2024 CPU applied.

Detection Strategies

• Inventory Java runtimes across the environment using software asset management and compare installed versions against the Oracle CPU advisory.
• Correlate application logs with network telemetry to identify integrity-violating operations triggered by external requests.
• Apply behavioral monitoring on Java service hosts to flag unexpected child processes, file modifications, or outbound connections initiated by java processes.

Monitoring Recommendations

• Enable verbose audit logging on application APIs that accept external data and feed those logs into a centralized analytics platform.
• Track Java runtime version drift continuously and alert when hosts run unpatched builds enumerated in the Oracle advisory.
• Review NetApp Security Advisory ntap-20240201-0002 for downstream product exposure in NetApp deployments.

How to Mitigate CVE-2024-20919

Immediate Actions Required

• Apply the Oracle January 2024 Critical Patch Update to all affected Java SE and GraalVM installations.
• Identify embedded JDKs bundled within third-party applications, since these are often missed during routine patching.
• Restrict network exposure of Java services that accept untrusted input until patches are deployed.

Patch Information

Oracle issued patches in the Oracle Security Alert January 2024. Upgrade Java SE to 8u401, 11.0.22, 17.0.10, or 21.0.2, and upgrade GraalVM to the corresponding January 2024 releases. NetApp publishes downstream guidance in NetApp Security Advisory ntap-20240201-0002 and NetApp Security Advisory ntap-20241108-0002.

Workarounds

• Place affected Java services behind a reverse proxy or web application firewall that enforces strict input validation on API parameters.
• Limit network exposure of Hotspot-backed APIs to trusted internal segments where feasible.
• Disable or remove unused Java runtimes from production hosts to reduce attack surface.

# Verify installed Java version against patched releases
java -version

# Example: list installed JDK packages on Debian/Ubuntu hosts
dpkg -l | grep -E 'jdk|jre|graalvm'

# Example: list installed JDK packages on RHEL/CentOS hosts
rpm -qa | grep -E 'jdk|jre|graalvm'