CVE-2021-28169Network attack vector

Information disclosure via double-decoded servlet paths

Published Jun 9, 2021 · Updated Aug 3, 2024

Information disclosure in Eclipse Jetty 9.4.40 and earlier, 10.0.2 and earlier, and 11.0.2 and earlier allows remote attackers to read files. ConcatServlet and WelcomeFilter decode a supplied path for a WEB-INF or META-INF check, then pass it to RequestDispatcher for a second decode, letting double encoding bypass the first check. Exploitation requires a reachable deployment of either component, and the resulting access is limited to protected web-application resources.

CVSS severity5.3
Medium
EPSS probability78.48%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in Eclipse Jetty 9.4.40 and earlier, 10.0.2 and earlier, and 11.0.2 and earlier allows remote attackers to read files. ConcatServlet and WelcomeFilter decode a supplied path for a WEB-INF or META-INF check, then pass it to RequestDispatcher for a second decode, letting double encoding bypass the first check. Exploitation requires a reachable deployment of either component, and the resulting access is limited to protected web-application resources.

The record

CVE
CVE-2021-28169
Published
Jun 9, 2021
Updated
Aug 3, 2024
Vendor
The Eclipse Foundation
Product
Eclipse Jetty
Classifications
CWE-200, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 9, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <=10.0.2
  2. Affected versionversion=unspecified <=11.0.2
  3. Affected versionversion=unspecified <=9.4.40

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Eclipse Foundation · Eclipse Jettyversion=unspecified <=10.0.2; version=unspecified <=11.0.2; version=unspecified <=9.4.40

Published CVSS scores

5.3Eclipse FoundationCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
5.0NIST NVDAV:N/AC:L/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 exploitUnconfirmed

Weakness, pattern, technique

CWE-200Exposure of Sensitive Information to an Unauthorized Actor
T1190Exploit Public-Facing Application

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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