Описание
OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. In versions 2.4.16 and prior, in a network-exposed cupsd with a shared target queue, an unauthorized client can send a Print-Job to that shared PostScript queue without authentication. The server accepts a page-border value supplied as textWithoutLanguage, preserves an embedded newline through option escaping and reparse, and then reparses the resulting second-line PPD: text as a trusted scheduler control record. A follow-up raw print job can therefore make the server execute an attacker-chosen existing binary such as /usr/bin/vim as lp. At time of publication, there are no publicly available patches.
A flaw was found in OpenPrinting CUPS. An unauthorized client can exploit this vulnerability by sending a specially crafted print job to a shared PostScript queue without authentication. The server improperly handles the page-border value, allowing an attacker to embed and reparse malicious text as a trusted scheduler control record. This can lead to arbitrary code execution with the privileges of the 'lp' user, potentially compromising the affected system.
Отчет
This issue is classified as moderate severity primarily because:
- Affected Component: The vulnerability specifically affects the core cups daemon package (which handles the print scheduler and target queues) and does not affect the utility libraries (cups-libs).
- Conditions for Exploitation: Exploitation requires a network-exposed CUPS daemon (cupsd) configured with an active, shared PostScript target queue. A remote, unauthenticated attacker must be able to reach this daemon over the network and submit a crafted print job to the shared queue.
- Impact Limitations: While the flaw allows for remote command execution, the execution is strictly limited to utilizing existing binaries already present on the system. Furthermore, these commands run under the restricted privileges of the unprivileged service user (lp) rather than the root or administrative user, preventing direct, full system compromise.
Меры по смягчению последствий
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 6 | cups | Out of support scope | ||
| Red Hat Enterprise Linux 7 | cups | Out of support scope | ||
| Red Hat OpenShift Container Platform 4 | openshift/ose-rhel-coreos-8 | Not affected | ||
| Red Hat Enterprise Linux 10 | cups | Fixed | RHSA-2026:39302 | 14.07.2026 |
| Red Hat Enterprise Linux 8 | cups | Fixed | RHSA-2026:36733 | 08.07.2026 |
| Red Hat Enterprise Linux 8 | cups | Fixed | RHSA-2026:36733 | 08.07.2026 |
| Red Hat Enterprise Linux 9 | cups | Fixed | RHSA-2026:39316 | 14.07.2026 |
| Red Hat Enterprise Linux 9 | cups | Fixed | RHSA-2026:39316 | 14.07.2026 |
| Red Hat Hardened Images | cups-main-2.4.17-1.hum1 | Fixed | RHSA-2026:8814 | 17.04.2026 |
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Дополнительная информация
Статус:
EPSS
6.4 Medium
CVSS3
Связанные уязвимости
OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. In versions 2.4.16 and prior, in a network-exposed cupsd with a shared target queue, an unauthorized client can send a Print-Job to that shared PostScript queue without authentication. The server accepts a page-border value supplied as textWithoutLanguage, preserves an embedded newline through option escaping and reparse, and then reparses the resulting second-line PPD: text as a trusted scheduler control record. A follow-up raw print job can therefore make the server execute an attacker-chosen existing binary such as /usr/bin/vim as lp. At time of publication, there are no publicly available patches.
OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. In versions 2.4.16 and prior, in a network-exposed cupsd with a shared target queue, an unauthorized client can send a Print-Job to that shared PostScript queue without authentication. The server accepts a page-border value supplied as textWithoutLanguage, preserves an embedded newline through option escaping and reparse, and then reparses the resulting second-line PPD: text as a trusted scheduler control record. A follow-up raw print job can therefore make the server execute an attacker-chosen existing binary such as /usr/bin/vim as lp. At time of publication, there are no publicly available patches.
OpenPrinting CUPS: Shared PostScript queue lets anonymous Print-Job requests reach `lp` code execution over the network
OpenPrinting CUPS is an open source printing system for Linux and othe ...
EPSS
6.4 Medium
CVSS3