SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

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.

MEDIUM 5.3EPSS 78.5%

Does this matter?

EPSS puts the probability of exploitation in the next 30 days at 78.5%, higher than 100% of all known CVEs. Patch or mitigate before the next change window.

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.

CVSS 3.1
5.3 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
EPSS
78.48% probability · 100th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-200
Affected
eclipse/jetty · debian/debian linux · oracle/communications cloud native core policy · oracle/rest data services · netapp/active iq unified manager · netapp/hci · netapp/management services for element software · netapp/snap creator framework
Source
emo@eclipse.org
EPSS trend
0%40%80%3 November 2026: 78.48%3 November 20263 November 2026

EPSS 78.5% since 3 November 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.