CVE-2021-30485Public exploitNetwork attack vector

Service crash via NULL dereference in ezxml_internal_dtd

Published Apr 11, 2021 · Updated Aug 3, 2024

NULL pointer dereference in ezXML 0.8.6 allows remote attackers to cause a service interrupt via crafted XML input. The ezxml_internal_dtd() parser passes a NULL pointer to strcmp() while processing the document's internal DTD, triggering a crash. Exploitation requires an application to parse attacker-supplied XML and user interaction with that parsing workflow; the documented impact is availability loss without data disclosure or modification.

CVSS severity6.5
Medium
EPSS probability1.12%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in ezXML 0.8.6 allows remote attackers to cause a service interrupt via crafted XML input. The ezxml_internal_dtd() parser passes a NULL pointer to strcmp() while processing the document's internal DTD, triggering a crash. Exploitation requires an application to parse attacker-supplied XML and user interaction with that parsing workflow; the documented impact is availability loss without data disclosure or modification.

The record

CVE
CVE-2021-30485
Published
Apr 11, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-476, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 11, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.5NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
4.3NVDAV:N/AC:M/Au:N/C:N/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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499Endpoint Denial of Service

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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