CVE-2022-23634 | Information Exposure when using Puma with Rails

Puma is a Ruby/Rack web server built for parallelism. Prior to `puma` version `5.6.2`, `puma` may not always call `close` on the response body. Rails, prior to version `7.0.2.2`, depended on the response body being closed in order for its `CurrentAttributes` implementation to work correctly. The combination of these two behaviors (Puma not closing the body + Rails' Executor implementation) causes information leakage. This problem is fixed in Puma versions 5.6.2 and 4.3.11. This problem is fixed in Rails versions 7.02.2, 6.1.4.6, 6.0.4.6, and 5.2.6.2. Upgrading to a patched Rails _or_ Puma version fixes the vulnerability.

Published: 2022-02-11 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2022-23634 is rated Moderate Risk (61.3/100): CVSS High severity, with medium exploitation likelihood (EPSS 2.09%). EPSS rose +1.61% over the last day, indicating growing attacker interest. 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-2022-23634

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 2026-06-15 0.48% 2.09% +1.61%
2 2026-05-11 0.44% 0.48% +0.04%
3 2026-04-07 — 0.44% —

Full EPSS history (25 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2022-23634

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.0 3.1 HIGH
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/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:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 1.6 5.8 [email protected]
5.9 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/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:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
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:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 2.2 3.6 [email protected]
4.3 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:N/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 8.6 2.9 [email protected]

Weakness enumeration for CVE-2022-23634

GitHub Security Advisory for CVE-2022-23634

GHSA-rmj8-8hhh-gv5h · Severity: high · Ecosystem: rubygems — Puma used with Rails may lead to Information Exposure

OS Trackers for CVE-2022-23634

vendor priority summary link
debian not yet assigned CVE-2022-23634 not yet assigned priority: Debian including 1 source packages (puma), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2022-23634
gentoo low CVE-2022-23634: 1 GLSA(s) (202208-28), 1 atom(s) (www-servers/puma); latest impact low. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2022-23634
redhat high — https://access.redhat.com/security/cve/CVE-2022-23634
suse medium — https://www.suse.com/security/cve/CVE-2022-23634/
ubuntu medium CVE-2022-23634 medium priority: Ubuntu including 1 source packages (puma), 13 status rows across 13 suites (focal, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): not-affected 6, ignored 4, released 2, needs-triage 1. https://ubuntu.com/security/CVE-2022-23634

Affected software / configurations for CVE-2022-23634

Vendor Product Version Raw CPE
puma puma < 4.3.11 cpe:2.3:a:puma:puma:*:*:*:*:*:ruby:*:*
puma puma >= 5.0.0, < 5.6.2 cpe:2.3:a:puma:puma:*:*:*:*:*:ruby:*:*
rubyonrails rails >= 5.0.0, < 5.2.6.2 cpe:2.3:a:rubyonrails:rails:*:*:*:*:*:*:*:*
rubyonrails rails >= 6.0.0, < 6.0.4.6 cpe:2.3:a:rubyonrails:rails:*:*:*:*:*:*:*:*
rubyonrails rails >= 6.1.0, < 6.1.4.6 cpe:2.3:a:rubyonrails:rails:*:*:*:*:*:*:*:*
rubyonrails rails >= 7.0.0, < 7.0.2.2 cpe:2.3:a:rubyonrails:rails:*:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
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:*:*:*:*:*:*:*
fedoraproject fedora 35 cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*
fedoraproject fedora 36 cpe:2.3:o:fedoraproject:fedora:36:*:*:*:*:*:*:*
fedoraproject fedora 37 cpe:2.3:o:fedoraproject:fedora:37:*:*:*:*:*:*:*

References for CVE-2022-23634

URL Tags
https://github.com/advisories/GHSA-rmj8-8hhh-gv5h Third Party Advisory
https://github.com/advisories/GHSA-wh98-p28r-vrc9 Mitigation Not Applicable Third Party Advisory
https://github.com/puma/puma/commit/b70f451fe8abc0cff192c065d549778452e155bb Patch Third Party Advisory
https://github.com/puma/puma/security/advisories/GHSA-rmj8-8hhh-gv5h Patch Third Party Advisory
https://groups.google.com/g/ruby-security-ann/c/FkTM-_7zSNA/m/K2RiMJBlBAAJ?utm_medium=email&utm_source=footer&pli=1 Mailing List Mitigation Patch Third Party Advisory
https://lists.debian.org/debian-lts-announce/2022/05/msg00034.html Mailing List Third Party Advisory
https://lists.debian.org/debian-lts-announce/2022/08/msg00015.html Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/F6YWGIIKL7KKTS3ZOAYMYPC7D6WQ5OA5/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/L7NESIBFCNSR3XH7LXDPKVMSUBNUB43G/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TUBFJ44NCKJ34LECZRAP4N5VL6USJSIB/
https://security.gentoo.org/glsa/202208-28 Third Party Advisory
https://www.debian.org/security/2022/dsa-5146 Third Party Advisory
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