CVE-2023-40167

CVE-2023-40167 is a medium-severity vulnerability in Eclipse Jetty with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-130.

Key facts

Description

Jetty is a Java based web server and servlet engine. Prior to versions 9.4.52, 10.0.16, 11.0.16, and 12.0.1, Jetty accepts the `+` character proceeding the content-length value in a HTTP/1 header field. This is more permissive than allowed by the RFC and other servers routinely reject such requests with 400 responses. There is no known exploit scenario, but it is conceivable that request smuggling could result if jetty is used in combination with a server that does not close the connection after sending such a 400 response. Versions 9.4.52, 10.0.16, 11.0.16, and 12.0.1 contain a patch for this issue. There is no workaround as there is no known exploit scenario.

Frequently asked questions

What is CVE-2023-40167?
Jetty is a Java based web server and servlet engine. Prior to versions 9.4.52, 10.0.16, 11.0.16, and 12.0.1, Jetty accepts the `+` character proceeding the content-length value in a HTTP/1 header field. This is more permissive than allowed by the RFC and other servers routinely reject such requests with 400 responses. There is no known exploit scenario, but it is conceivable that request smuggling could result if jetty is used in combination with a server that does not close the connection after sending such a 400 response. Versions 9.4.52, 10.0.16, 11.0.16, and 12.0.1 contain a patch for this issue. There is no workaround as there is no known exploit scenario.
How severe is CVE-2023-40167?
CVE-2023-40167 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 none, integrity low, and availability none.
Is CVE-2023-40167 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (61st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-40167?
CVE-2023-40167 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-2023-40167?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2023-40167 published?
CVE-2023-40167 was published on 2023-09-15 and last updated on 2026-06-17.

References

Affected products (10)

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Threat intelligence

Threat-intel indicators referencing this CVE: