CVE-2024-21217: Oracle Java SE · Difficult to exploit vulnerability allows unauthenticated attacker with network access via multiple
Affects Oracle Java SESource CVE Database V5
Not known to be exploited · CVSS 3.7 Low.
Data as of 26 Oct 2026, 06:26 UTC
- EPSS
- 1.1% chance of exploitation in 30 days – higher than 66% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:LExploitation evidence
Disclosed: evidence found.
CVE published 15 Oct 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.
What to do
AI-suggested
European organizations should implement the following specific mitigations: 1) Apply Oracle's security updates promptly once patches become available, as no patches are currently linked but are expected given the disclosure. 2) Audit and restrict network exposure of Java serialization APIs and services, limiting access to trusted networks and clients only. 3) Disable or remove legacy Java Web Start and applet technologies where possible, as these increase attack surface by running untrusted code in sandboxed environments. 4) Implement input validation and filtering on serialized data inputs to prevent malicious payloads from reaching vulnerable components. 5) Employ runtime monitoring and anomaly detection focused on Java serialization activities to identify unusual patterns indicative of exploitation attempts. 6) Use application-layer firewalls or Web Application Firewalls (WAFs) with rules targeting suspicious serialized data traffic. 7) Conduct code reviews and security testing for custom serialization logic to ensure it does not introduce similar vulnerabilities. 8) Maintain an inventory of Java versions in use across the organization to prioritize patching and mitigation efforts effectively.
Description
Vulnerability in the Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition product of Oracle Java SE (component: Serialization). Supported versions that are affected are Oracle Java SE: 8u421, 8u421-perf, 11.0.24, 17.0.12, 21.0.4, 23; Oracle GraalVM for JDK: 17.0.12, 21.0.4, 23; Oracle GraalVM Enterprise Edition: 20.3.15 and 21.3.11. Difficult to exploit vulnerability allows unauthenticated attacker with network access via multiple protocols to compromise Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition. Successful attacks of this vulnerability can result in unauthorized ability to cause a partial denial of service (partial DOS) of Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition. Note: This vulnerability can be exploited by using APIs in the specified Component, e.g., through a web service which supplies data to the APIs. This vulnerability also applies to Java deployments, typically in clients running sandboxed Java Web Start applications or sandboxed Java applets, that load and run untrusted code (e.g., code that comes from the internet) and rely on the Java sandbox for security. CVSS 3.1 Base Score 3.7 (Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L).