CVE-2021-28169

CVE-2021-28169 is a medium-severity vulnerability in Eclipse Jetty with a CVSS 3.x base score of 5.3. Its EPSS exploit-prediction score of 78% places it in the 100th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-200.

Key facts

Description

For Eclipse Jetty versions <= 9.4.40, <= 10.0.2, <= 11.0.2, it is possible for requests to the ConcatServlet with a doubly encoded path to access protected resources within the WEB-INF directory. For example a request to `/concat?/%2557EB-INF/web.xml` can retrieve the web.xml file. This can reveal sensitive information regarding the implementation of a web application.

Frequently asked questions

What is CVE-2021-28169?
For Eclipse Jetty versions <= 9.4.40, <= 10.0.2, <= 11.0.2, it is possible for requests to the ConcatServlet with a doubly encoded path to access protected resources within the WEB-INF directory. For example a request to `/concat?/%2557EB-INF/web.xml` can retrieve the web.xml file. This can reveal sensitive information regarding the implementation of a web application.
How severe is CVE-2021-28169?
CVE-2021-28169 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2021-28169 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 78% (100th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-28169?
CVE-2021-28169 primarily affects Eclipse Jetty. In total, 10 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-28169?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-28169 published?
CVE-2021-28169 was published on 2021-06-09 and last updated on 2026-06-17.

References

Affected products (10)

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Threat intelligence

Threat-intel indicators referencing this CVE: