CVE-2021-23463Public exploitNetwork attack vector

Data disclosure and service interruption via SQLXML parsing

Published Dec 10, 2021 · Updated Sep 17, 2024

XXE injection in H2 Database Engine 1.4.198 through 2.0.201 allows attackers to read data or interrupt service via crafted SQLXML. JdbcResultSet.getSQLXML() wraps returned string data in JdbcSQLXML, whose getSource(DOMSource.class) path builds a DOM without disabling external entity resolution. Exploitation requires attacker-controlled XML to reach a queried field and application code to request a DOMSource; successful resolution can expose local resources or exhaust parser resources.

CVSS severity9.1
Critical
EPSS probability2.70%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

XXE injection in H2 Database Engine 1.4.198 through 2.0.201 allows attackers to read data or interrupt service via crafted SQLXML. JdbcResultSet.getSQLXML() wraps returned string data in JdbcSQLXML, whose getSource(DOMSource.class) path builds a DOM without disabling external entity resolution. Exploitation requires attacker-controlled XML to reach a queried field and application code to request a DOMSource; successful resolution can expose local resources or exhaust parser resources.

The record

CVE
CVE-2021-23463
Published
Dec 10, 2021
Updated
Sep 17, 2024
Vendor
H2 Database Engine
Product
H2 Database Engine
Classifications
CWE-611
Attack vector
network
Privileges
Unavailable

Timeline

How it unfolded

  1. Dec 10, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 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=0 <unspecified
  2. Affected versionversion=unspecified <2.0.202

What conditions does exploitation require?

Attack vectornetwork
Required privilegesUnavailable in this record.

What is affected?

H2 Database Engine · H2 Database Engineversion=0 <unspecified; version=unspecified <2.0.202

Published CVSS scores

9.1NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
8.1GitHub Advisory DatabaseCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
6.4NVDAV:N/AC:L/Au:N/C:P/I:N/A:P

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.

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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
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-611Improper Restriction of XML External Entity Reference

Public exploit references

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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