CVE-2021-28110Network attack vector

Unauthenticated service interruption via XML entity expansion

Published Mar 19, 2021 · Updated Aug 3, 2024

XXE in /exec in Compass Plus TranzWare e-Commerce Payment Gateway before 3.1.27.5 allows remote attackers to interrupt service. The /exec XML parser expands attacker-controlled external entities without adequate restriction, allowing recursive references to exhaust memory or CPU. No authentication or user interaction is required, and published impact evidence is limited to denial of service rather than data access or modification.

CVSS severity7.5
High
EPSS probability0.98%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

XXE in /exec in Compass Plus TranzWare e-Commerce Payment Gateway before 3.1.27.5 allows remote attackers to interrupt service. The /exec XML parser expands attacker-controlled external entities without adequate restriction, allowing recursive references to exhaust memory or CPU. No authentication or user interaction is required, and published impact evidence is limited to denial of service rather than data access or modification.

The record

CVE
CVE-2021-28110
Published
Mar 19, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-611, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 19, 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

7.5NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.0NVDAV:N/AC:L/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.

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

CWE-611Improper Restriction of XML External Entity Reference
T1499.004Application or System Exploitation

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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