CVE-2021-1993Network attack vector

Unauthorized data modification via undisclosed Java VM flaw

Published Jan 20, 2021 · Updated Sep 26, 2024

A Java VM flaw in Oracle Database 12.1.0.2, 12.2.0.1, 18c, and 19c allows remote authenticated users to modify accessible data. Oracle has not published the faulty Java VM operation or the untrusted input that triggers it. Exploitation requires Create Session privilege, Oracle Net access, high attack complexity, and interaction by a person other than the attacker; successful attacks create, delete, or modify critical or Java VM-accessible data.

CVSS severity4.8
Medium
EPSS probability0.81%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A Java VM flaw in Oracle Database 12.1.0.2, 12.2.0.1, 18c, and 19c allows remote authenticated users to modify accessible data. Oracle has not published the faulty Java VM operation or the untrusted input that triggers it. Exploitation requires Create Session privilege, Oracle Net access, high attack complexity, and interaction by a person other than the attacker; successful attacks create, delete, or modify critical or Java VM-accessible data.

The record

CVE
CVE-2021-1993
Published
Jan 20, 2021
Updated
Sep 26, 2024
Vendor
Oracle Corporation
Product
Oracle Database
Classifications
T1565
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 20, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 26, 2024Record 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=12.1.0.2
  2. Affected versionversion=12.2.0.1
  3. Affected versionversion=18c
  4. Affected versionversion=19c

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Oracle Corporation · Oracle Databaseversion=12.1.0.2; version=12.2.0.1; version=18c; version=19c

Published CVSS scores

4.8Oracle CorporationCVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:H/A:N
3.5NISTAV:N/AC:H/Au:S/C:N/I:P/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1565Data Manipulation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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