CVE-2021-28684Public exploitNetwork attack vector

Local-file exfiltration via external entity resolution

Published Jun 21, 2021 · Updated Aug 3, 2024

XML external entity injection in ConeXware PowerArchiver before 20.10.02 allows remote attackers to exfiltrate local files via crafted XML. The XML parser resolves external entity references from untrusted documents, permitting a referenced local file to be read and transmitted to an external network resource. Exploitation requires user interaction with attacker-supplied XML; the established impact is local-file disclosure, not modification or service interruption.

CVSS severity4.3
Medium
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

XML external entity injection in ConeXware PowerArchiver before 20.10.02 allows remote attackers to exfiltrate local files via crafted XML. The XML parser resolves external entity references from untrusted documents, permitting a referenced local file to be read and transmitted to an external network resource. Exploitation requires user interaction with attacker-supplied XML; the established impact is local-file disclosure, not modification or service interruption.

The record

CVE
CVE-2021-28684
Published
Jun 21, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-611, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 21, 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

4.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
4.3NIST NVDAV:N/AC:M/Au:N/C:P/I:N/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 exploitPublished

Weakness, pattern, technique

CWE-611Improper Restriction of XML External Entity Reference
T1203Exploitation for Client Execution

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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