CVE-2021-36943

Local file disclosure via REST API XXE

Published Aug 12, 2021 · Updated Aug 10, 2026

XML external entity injection in Microsoft Azure CycleCloud before 8.2.0 allows local users to read limited data through the REST API. The REST API's XML parser resolves attacker-controlled external entity references instead of rejecting them. Exploitation requires local access to the application server, and Microsoft's published assessment limits the consequence to confidentiality loss.

CVSS severity4.0
Medium
EPSS probability0.82%
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 Microsoft Azure CycleCloud before 8.2.0 allows local users to read limited data through the REST API. The REST API's XML parser resolves attacker-controlled external entity references instead of rejecting them. Exploitation requires local access to the application server, and Microsoft's published assessment limits the consequence to confidentiality loss.

The record

CVE
CVE-2021-36943
Published
Aug 12, 2021
Updated
Aug 10, 2026
Vendor
Microsoft
Product
Azure CycleCloud
Classifications
CWE-269, T1005
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 12, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 10, 2026Record 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=8.2.0 <8.2.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Microsoft · Azure CycleCloudversion=8.2.0 <8.2.0

Published CVSS scores

4.0MicrosoftCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
7.8NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
4.6NVDAV:L/AC:L/Au:N/C:P/I:P/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)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-269Improper Privilege Management
T1005Data from Local System

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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