CVE-2021-28235Network attack vector

Credential disclosure via unauthenticated debug request endpoint

Published Apr 4, 2023 · Updated Jul 9, 2026

Credential disclosure in etcd 3.4.10 allows remote attackers to obtain user passwords through the unauthenticated debug request endpoint. Authenticate retains the supplied password in its request object after validation, and /debug/requests renders that object when debug logging is enabled. Reachability requires enabled authentication, debug-level logging, a client authentication request, and network access to the debug HTTP endpoint; exposed credentials grant the victim user's privileges.

CVSS severity9.8
Critical
EPSS probability1.62%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Credential disclosure in etcd 3.4.10 allows remote attackers to obtain user passwords through the unauthenticated debug request endpoint. Authenticate retains the supplied password in its request object after validation, and /debug/requests renders that object when debug logging is enabled. Reachability requires enabled authentication, debug-level logging, a client authentication request, and network access to the debug HTTP endpoint; exposed credentials grant the victim user's privileges.

The record

CVE
CVE-2021-28235
Published
Apr 4, 2023
Updated
Jul 9, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-287, T1552
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 4, 2023CVE publishedPublication date reported by the CVE source.
  2. Jul 9, 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?

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

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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 exploitUnconfirmed

Weakness, pattern, technique

CWE-287Improper Authentication
T1552Unsecured Credentials

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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