NVD / CVE Program· CNA GitHub_M

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

Noroxi assessment

Priority: Monitor (action score 28/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 1.3% (FIRST EPSS); higher than 72.2% of all records.
Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
According to CISA the attack is automatable: targets can be found by mass scanning.
Fixed version: cups (AlmaLinux:8) 1:2.2.6-54.el8_9; cups-client (AlmaLinux:8) 1:2.2.6-54.el8_9; cups-devel (AlmaLinux:8) 1:2.2.6-54.el8_9.

Low priority for now. Upgrade to cups (AlmaLinux:8) 1:2.2.6-54.el8_9; cups-client (AlmaLinux:8) 1:2.2.6-54.el8_9; cups-devel (AlmaLinux:8) 1:2.2.6-54.el8_9 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

HighCVSS 7.1 · v3.1—No exploit Fix available

Memory safety

Published: Jun 22, 2023
Updated: Jun 17, 2026
EPSS: 1.3% · 72th percentile
CWE: CWE-416

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 28 / 40 · 7.1 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 1.3%

CISA SSVC decision

Exploitation: proof of concept
Automatable: yes
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: 7.1
CNA · GitHub_M: 5.3; 1.8 point gap

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
openprinting	cups	cpe:2.3:a:openprinting:cups
fedoraproject	fedora	cpe:2.3:o:fedoraproject:fedora
debian	debian linux	cpe:2.3:o:debian:debian_linux
apple	macos	cpe:2.3:o:apple:macos

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

apple macosbefore 11.7.9
apple macos13.0 and later · before 13.5
apple macos12.0.0 and later · before 12.6.8
debian debian linux10.0
fedoraproject fedora37
fedoraproject fedora38
openprinting cups2.2.0 and later · before 2.4.6

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

OpenPrinting cups
- >= 2.0.0, < 2.4.6affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
AlmaLinux:8	cups	before 1:2.2.6-54.el8_9	1:2.2.6-54.el8_9
AlmaLinux:8	cups-client	before 1:2.2.6-54.el8_9	1:2.2.6-54.el8_9
AlmaLinux:8	cups-devel	before 1:2.2.6-54.el8_9	1:2.2.6-54.el8_9
AlmaLinux:8	cups-filesystem	before 1:2.2.6-54.el8_9	1:2.2.6-54.el8_9
AlmaLinux:8	cups-ipptool	before 1:2.2.6-54.el8_9	1:2.2.6-54.el8_9
AlmaLinux:8	cups-libs	before 1:2.2.6-54.el8_9	1:2.2.6-54.el8_9
AlmaLinux:8	cups-lpd	before 1:2.2.6-54.el8_9	1:2.2.6-54.el8_9
AlmaLinux:9	cups	before 1:2.3.3op2-21.el9	1:2.3.3op2-21.el9
AlmaLinux:9	cups-client	before 1:2.3.3op2-21.el9	1:2.3.3op2-21.el9
AlmaLinux:9	cups-devel	before 1:2.3.3op2-21.el9	1:2.3.3op2-21.el9
AlmaLinux:9	cups-filesystem	before 1:2.3.3op2-21.el9	1:2.3.3op2-21.el9
AlmaLinux:9	cups-ipptool	before 1:2.3.3op2-21.el9	1:2.3.3op2-21.el9
AlmaLinux:9	cups-libs	before 1:2.3.3op2-21.el9	1:2.3.3op2-21.el9
AlmaLinux:9	cups-lpd	before 1:2.3.3op2-21.el9	1:2.3.3op2-21.el9
AlmaLinux:9	cups-printerapp	before 1:2.3.3op2-21.el9	1:2.3.3op2-21.el9
Alpine:v3.15	cups	from 2.2.0 · before 2.3.3-r8	2.3.3-r8
Alpine:v3.16	cups	from 2.2.0 · before 2.4.2-r2	2.4.2-r2
Alpine:v3.17	cups	from 2.2.0 · before 2.4.2-r3	2.4.2-r3
Debian:10	cups	before 2.2.10-6+deb10u8	2.2.10-6+deb10u8
Debian:12	cups	before 2.4.2-3+deb12u1	2.4.2-3+deb12u1
Debian:13	cups	before 2.4.2-5	2.4.2-5
openSUSE:Leap Micro 5.3	cups	before 2.2.7-150000.3.46.1	2.2.7-150000.3.46.1
openSUSE:Tumbleweed	cups	before 2.4.2-6.1	2.4.2-6.1
Red Hat:enterprise_linux:8::appstream	cups	before 1:2.2.6-54.el8_9	1:2.2.6-54.el8_9

+56

Same product

openprinting: all records

Other highest-scoring records for the same primary product.

CVE-2025-58060cups has Authentication bypass with AuthType Negotiate
32Monitor
CVE-2023-4504OpenPrinting CUPS/libppd Postscript Parsing Heap Overflow
28Monitor
CVE-2024-35235Cupsd Listen arbitrary chmod 0140777
27Monitor

Published before and after this one in the same product

← EarlierCVE-2023-32324Jun 1, 2023 · OpenPrinting CUPS vulnerable to heap buffer overflow
22Monitor
Later →CVE-2025-58364Sep 11, 2025 · cups: Remote DoS via null dereference
26Monitor
Later →CVE-2025-58436Nov 29, 2025 · OpenPrinting CUPS slow client can halt cupsd, leading to a possible DoS attack
22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
almalinux:cups	1:2.3.3op2-21.el9 · AlmaLinux:9	Package registry (OSV)
almalinux:cups-client	1:2.3.3op2-21.el9 · AlmaLinux:9	Package registry (OSV)
almalinux:cups-devel	1:2.3.3op2-21.el9 · AlmaLinux:9	Package registry (OSV)
almalinux:cups-filesystem	1:2.3.3op2-21.el9 · AlmaLinux:9	Package registry (OSV)
almalinux:cups-ipptool	1:2.3.3op2-21.el9 · AlmaLinux:9	Package registry (OSV)
almalinux:cups-libs	1:2.3.3op2-21.el9 · AlmaLinux:9	Package registry (OSV)
almalinux:cups-lpd	1:2.3.3op2-21.el9 · AlmaLinux:9	Package registry (OSV)
almalinux:cups-printerapp	1:2.3.3op2-21.el9 · AlmaLinux:9	Package registry (OSV)
alpine:cups	2.3.3-r8 · Alpine:v3.15	Package registry (OSV)
debian:cups	2.4.2-3+deb12u1 · Debian:12	Package registry (OSV)
opensuse:cups	2.2.7-150000.3.46.1 · openSUSE:Leap Micro 5.3	Package registry (OSV)
red hat:cups	1:2.3.3op2-21.el9 · Red Hat:enterprise_linux:9::appstream	Package registry (OSV)
red hat:cups-client	1:2.3.3op2-21.el9 · Red Hat:enterprise_linux:9::appstream	Package registry (OSV)
red hat:cups-client-debuginfo	1:2.3.3op2-21.el9 · Red Hat:enterprise_linux:9::appstream	Package registry (OSV)
red hat:cups-debuginfo	1:2.3.3op2-21.el9 · Red Hat:enterprise_linux:9::appstream	Package registry (OSV)
red hat:cups-debugsource	1:2.3.3op2-21.el9 · Red Hat:enterprise_linux:9::appstream	Package registry (OSV)
red hat:cups-devel	1:2.3.3op2-21.el9 · Red Hat:enterprise_linux:9::appstream	Package registry (OSV)
red hat:cups-filesystem	1:2.3.3op2-21.el9 · Red Hat:enterprise_linux:9::appstream	Package registry (OSV)
red hat:cups-ipptool	1:2.3.3op2-21.el9 · Red Hat:enterprise_linux:9::appstream	Package registry (OSV)
red hat:cups-ipptool-debuginfo	1:2.3.3op2-21.el9 · Red Hat:enterprise_linux:9::appstream	Package registry (OSV)
red hat:cups-libs-debuginfo	1:2.3.3op2-21.el9 · Red Hat:enterprise_linux:9::appstream	Package registry (OSV)
red hat:cups-lpd	1:2.3.3op2-21.el9 · Red Hat:enterprise_linux:9::appstream	Package registry (OSV)
red hat:cups-lpd-debuginfo	1:2.3.3op2-21.el9 · Red Hat:enterprise_linux:9::appstream	Package registry (OSV)
suse:cups	2.2.7-150000.3.46.1 · SUSE:Linux Enterprise Micro 5.3	Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

OpenPrinting/cupscommit 9809947

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

Someone with local access to the system can trigger it.
A low-privileged account is enough.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: high · data can be read
Integrity: none
Availability: high · the service can be disrupted

Attack vector: Local
Attack complexity: Low
Privileges required: Low
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: None
Availability impact: High

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

nvd-primary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1free(dev->buf);
2/* ... another thread is still running ... */
3process(dev->buf);

Fixed

1lock(&dev->lock);
2free(dev->buf);
3dev->buf = NULL;
4unlock(&dev->lock);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

Fix✗ → ✓Sep 28, 2026, 10:46 PM UTC

For records you follow, these changes also arrive as notifications. →

References

www.openwall.com/lists/oss-security/2023/06/23/10

Show all references (9 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records