CVE-2023-21937Network attack vector

Unauthorized data modification via null-character truncation

Published Apr 18, 2023 · Updated Feb 13, 2025

Improper input validation in Oracle Java SE 8u361, 8u361-perf, 11.0.18, 17.0.6, and 20 allows remote attackers to alter application data. Platform-facing routines accept Java strings containing embedded null characters, causing native operations to truncate them instead of rejecting them. Exploitation requires crafted data to reach affected APIs through untrusted sandboxed code or a service, enabling unauthorized updates, insertions, or deletions.

CVSS severity3.7
Low
EPSS probability1.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in Oracle Java SE 8u361, 8u361-perf, 11.0.18, 17.0.6, and 20 allows remote attackers to alter application data. Platform-facing routines accept Java strings containing embedded null characters, causing native operations to truncate them instead of rejecting them. Exploitation requires crafted data to reach affected APIs through untrusted sandboxed code or a service, enabling unauthorized updates, insertions, or deletions.

The record

CVE
CVE-2023-21937
Published
Apr 18, 2023
Updated
Feb 13, 2025
Vendor
Oracle Corporation
Product
Java Platform, Standard Edition (Java SE)
Classifications
T1203, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 18, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 13, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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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:20.3.9
  2. Affected versionversion=Oracle GraalVM Enterprise Edition:21.3.5
  3. Affected versionversion=Oracle GraalVM Enterprise Edition:22.3.1
  4. Affected versionversion=Oracle Java SE:11.0.18
  5. Affected versionversion=Oracle Java SE:17.0.6
  6. Affected versionversion=Oracle Java SE:20
  7. Affected versionversion=Oracle Java SE:8u361
  8. Affected versionversion=Oracle Java SE:8u361-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:20.3.9; version=Oracle GraalVM Enterprise Edition:21.3.5; version=Oracle GraalVM Enterprise Edition:22.3.1; version=Oracle Java SE:11.0.18; version=Oracle Java SE:17.0.6; version=Oracle Java SE:20; version=Oracle Java SE:8u361; version=Oracle Java SE:8u361-perf

Published CVSS scores

3.7Oracle CorporationCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1203Exploitation for Client Execution
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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