CVE-2023-34241 | CUPS vulnerable to use-after-free in cupsdAcceptClient()

Exp

OpenPrinting CUPS is a standards-based, open source printing system for Linux and other Unix-like operating systems. Starting in version 2.0.0 and prior to version 2.4.6, CUPS logs data of free memory to the logging service AFTER the connection has been closed, when it should have logged the data right before. This is a use-after-free bug that impacts the entire cupsd process. The exact cause of this issue is the function `httpClose(con->http)` being called in `scheduler/client.c`. The problem is that httpClose always, provided its argument is not null, frees the pointer at the end of the call, only for cupsdLogClient to pass the pointer to httpGetHostname. This issue happens in function `cupsdAcceptClient` if LogLevel is warn or higher and in two scenarios: there is a double-lookup for the IP Address (HostNameLookups Double is set in `cupsd.conf`) which fails to resolve, or if CUPS is compiled with TCP wrappers and the connection is refused by rules from `/etc/hosts.allow` and `/etc/hosts.deny`. Version 2.4.6 has a patch for this issue.

Published: 2023-06-22 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-34241 is rated Exploit Available (50/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.06%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

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

Public exploit references (Exploit-DB) for CVE-2023-34241

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2023-34241

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 2026-05-06 0.05% 0.06% +0.01%
2 2025-11-21 0.91% 0.05% -0.86%
3 2025-11-18 — 0.91% —

Full EPSS history (16 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-34241

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:N/A:L 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:N)
Data isn’t meaningfully altered or forged.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 3.9 1.4 [email protected]
7.1 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
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:L)
A normal user session is enough; they don’t have to be admin.
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:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 5.2 [email protected]

Weakness enumeration for CVE-2023-34241

OS Trackers for CVE-2023-34241

vendor priority summary link
alpine high CVE-2023-34241: 1 source package rows (cups); 36 state rows across 6 repos (3.17-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 1, open 35. https://security.alpinelinux.org/vuln/CVE-2023-34241
debian not yet assigned CVE-2023-34241 not yet assigned priority: Debian including 1 source packages (cups), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2023-34241
gentoo high CVE-2023-34241: 1 GLSA(s) (202402-17), 1 atom(s) (net-print/cups); latest impact high. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2023-34241
redhat medium — https://access.redhat.com/security/cve/CVE-2023-34241
suse high CVE-2023-34241 severity important: SUSE including 304 source package names (6.0-baremetal:glibc-2.38-slfo.1.1_4.1, 6.0-base:glibc-2.38-slfo.1.1_4.1, …), 1002 product×package rows across 263 product lines (Container rancher/elemental-channel/sl-micro, Container suse/kiosk/firefox-esr, … (263 product lines)): Fixed 832, Known Affected 160, Known Not Affected 10. https://www.suse.com/security/cve/CVE-2023-34241/
ubuntu medium CVE-2023-34241 medium priority: Ubuntu including 1 source packages (cups), 8 status rows across 8 suites (bionic, focal, jammy, kinetic, lunar, trusty, upstream, xenial): released 6, ignored 1, needs-triage 1. https://ubuntu.com/security/CVE-2023-34241

Affected software / configurations for CVE-2023-34241

Vendor Product Version Raw CPE
openprinting cups >= 2.2.0, < 2.4.6 cpe:2.3:a:openprinting:cups:*:*:*:*:*:*:*:*
fedoraproject fedora 37 cpe:2.3:o:fedoraproject:fedora:37:*:*:*:*:*:*:*
fedoraproject fedora 38 cpe:2.3:o:fedoraproject:fedora:38:*:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
apple macos < 11.7.9 cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:*
apple macos >= 12.0.0, < 12.6.8 cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:*
apple macos >= 13.0, < 13.5 cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:*

References for CVE-2023-34241

URL Tags
http://www.openwall.com/lists/oss-security/2023/06/23/10 Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2023/06/26/1 Mailing List Third Party Advisory
https://github.com/OpenPrinting/cups/commit/9809947a959e18409dcf562a3466ef246cb90cb2 Patch
https://github.com/OpenPrinting/cups/releases/tag/v2.4.6 Release Notes
https://github.com/OpenPrinting/cups/security/advisories/GHSA-qjgh-5hcq-5f25 Exploit Patch Vendor Advisory
https://lists.debian.org/debian-lts-announce/2023/06/msg00038.html Mailing List
https://lists.fedoraproject.org/archives/list/[email protected]/message/7I7DWGYGEMBNLZF5UQBMF3SONR37YUBN/ Mailing List
https://lists.fedoraproject.org/archives/list/[email protected]/message/TBIYKDS3UG3W4Z7YOHTR2AWFNBRYPNYY/ Mailing List Third Party Advisory
https://support.apple.com/kb/HT213843 Third Party Advisory
https://support.apple.com/kb/HT213844 Third Party Advisory
https://support.apple.com/kb/HT213845 Third Party Advisory
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