CVE-2024-20952Network attack vector

Data disclosure and modification via RSA timing oracle

Published Jan 16, 2024 · Updated Nov 3, 2025

RSA padding validation in Oracle Java SE 8u391, 8u391-perf, 11.0.21, 17.0.9, and 21.0.1 allows remote attackers to read or alter data over TLS. The TLS RSA premaster-secret unwrap path exposes distinguishable padding and version-validation behavior instead of normalizing failures, creating a timing oracle. Exploitation requires difficult timing measurements against an application that passes untrusted input into Security APIs or runs sandboxed untrusted code; trusted-code-only servers are not exposed through the sandbox route.

CVSS severity7.4
High
EPSS probability0.92%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

RSA padding validation in Oracle Java SE 8u391, 8u391-perf, 11.0.21, 17.0.9, and 21.0.1 allows remote attackers to read or alter data over TLS. The TLS RSA premaster-secret unwrap path exposes distinguishable padding and version-validation behavior instead of normalizing failures, creating a timing oracle. Exploitation requires difficult timing measurements against an application that passes untrusted input into Security APIs or runs sandboxed untrusted code; trusted-code-only servers are not exposed through the sandbox route.

The record

CVE
CVE-2024-20952
Published
Jan 16, 2024
Updated
Nov 3, 2025
Vendor
Oracle Corporation
Product
Java Platform, Standard Edition (Java SE)
Classifications
CWE-416, CWE-284, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 16, 2024CVE publishedPublication date reported by the CVE source.
  2. Nov 3, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Oracle GraalVM Enterprise Edition:20.3.12
  2. Affected versionversion=Oracle GraalVM Enterprise Edition:21.3.8
  3. Affected versionversion=Oracle GraalVM Enterprise Edition:22.3.4
  4. Affected versionversion=Oracle GraalVM for JDK:17.0.9
  5. Affected versionversion=Oracle GraalVM for JDK:21.0.1
  6. Affected versionversion=Oracle Java SE:11.0.21
  7. Affected versionversion=Oracle Java SE:17.0.9
  8. Affected versionversion=Oracle Java SE:21.0.1
  9. Affected versionversion=Oracle Java SE:8u391
  10. Affected versionversion=Oracle Java SE:8u391-perf

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Oracle Corporation · Java Platform, Standard Edition (Java SE)version=Oracle GraalVM Enterprise Edition:20.3.12; version=Oracle GraalVM Enterprise Edition:21.3.8; version=Oracle GraalVM Enterprise Edition:22.3.4; version=Oracle GraalVM for JDK:17.0.9; version=Oracle GraalVM for JDK:21.0.1; version=Oracle Java SE:11.0.21; version=Oracle Java SE:17.0.9; version=Oracle Java SE:21.0.1; version=Oracle Java SE:8u391; version=Oracle Java SE:8u391-perf

Published CVSS scores

7.4Oracle CorporationCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free
CWE-284Improper Access Control
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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