CVE-2023-40167 | Jetty accepts "+" prefixed value in Content-Length

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.

Published: 2023-09-15 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-40167 is rated Moderate Risk (52.4/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 4.58%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2023-40167

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-03 4.70% 4.58% -0.12%
2 2026-05-27 4.96% 4.70% -0.26%
3 2026-05-22 — 4.96% —

Full EPSS history (49 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-40167

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 1.4 [email protected]
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 1.4 [email protected]

Weakness enumeration for CVE-2023-40167

GitHub Security Advisory for CVE-2023-40167

GHSA-hmr7-m48g-48f6 · Severity: medium · Ecosystem: maven — Jetty accepts "+" prefixed value in Content-Length

OS Trackers for CVE-2023-40167

vendor priority summary link
debian not yet assigned CVE-2023-40167 not yet assigned priority: Debian including 1 source packages (jetty9), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2023-40167
redhat medium — https://access.redhat.com/security/cve/CVE-2023-40167
suse medium CVE-2023-40167 severity moderate: SUSE including 58 source package names (jetty-annotations-9.4.53-1.1, jetty-annotations-9.4.53-150200.3.22.1, …), 234 product×package rows across 21 product lines (Image server-image, SUSE Enterprise Storage 7.1, … (21 product lines)): Fixed 234. https://www.suse.com/security/cve/CVE-2023-40167/
ubuntu medium CVE-2023-40167 medium priority: Ubuntu including 1 source packages (jetty9), 12 status rows across 12 suites (bionic, focal, jammy, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): needed 4, not-affected 4, ignored 3, released 1. https://ubuntu.com/security/CVE-2023-40167

Affected software / configurations for CVE-2023-40167

Vendor Product Version Raw CPE
eclipse jetty >= 9.0.0, < 9.4.52 cpe:2.3:a:eclipse:jetty:*:*:*:*:*:*:*:*
eclipse jetty >= 10.0.0, < 10.0.16 cpe:2.3:a:eclipse:jetty:*:*:*:*:*:*:*:*
eclipse jetty >= 11.0.0, < 11.0.16 cpe:2.3:a:eclipse:jetty:*:*:*:*:*:*:*:*
eclipse jetty 12.0.0 cpe:2.3:a:eclipse:jetty:12.0.0:-:*:*:*:*:*:*
eclipse jetty 12.0.0 cpe:2.3:a:eclipse:jetty:12.0.0:beta0:*:*:*:*:*:*
eclipse jetty 12.0.0 cpe:2.3:a:eclipse:jetty:12.0.0:beta1:*:*:*:*:*:*
eclipse jetty 12.0.0 cpe:2.3:a:eclipse:jetty:12.0.0:beta2:*:*:*:*:*:*
eclipse jetty 12.0.0 cpe:2.3:a:eclipse:jetty:12.0.0:beta3:*:*:*:*:*:*
eclipse jetty 12.0.0 cpe:2.3:a:eclipse:jetty:12.0.0:beta4:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
debian debian_linux 11.0 cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*
debian debian_linux 12.0 cpe:2.3:o:debian:debian_linux:12.0:*:*:*:*:*:*:*

References for CVE-2023-40167

cvelogic Threat Intelligence