CVE-2024-47176 Scanner

CUPS, the Common Unix Printing System, is a widely used open-source printing system that enables users to manage print jobs and queues. It is primarily used in Unix-like operating systems such as Linux and macOS to support printing from these environments. The software serves as a server-client infrastructure, providing network printing capabilities to share printers and printing resources within a network. Due to its open-source nature, CUPS has been integrated into many Unix-based operating systems, making it a popular choice for both home and enterprise environments. system administrators in charge of networked printing infrastructure rely on CUPS for a seamless printing experience across different printer types and operating systems. Overall, CUPS' multi-faceted functionality makes it a crucial component of network printer management tasks.

This scanner detects vulnerabilities related to remote code execution in the CUPS printing system. The identified vulnerability allows an attacker to exploit the network printing functionality within cups-browsed. This issue arises when the CUPS service listens on INADDR_ANY port 631, permitting unauthorized access to network packets from potentially malicious sources. Threat actors use the opportunity to introduce malicious printers into the system by leveraging bugs in cups-browsed. Once the exploit chain is activated, it can lead to arbitrary command execution on the target machine, providing attackers substantial control over the affected system without authentication. The open exposure on the public internet increases the potential threat, amplifying the network's vulnerability.

The vulnerability primarily resides in the IPP (Internet Printing Protocol) service endpoint, which is responsible for handling printer attributes requests from users or network elements. Attackers may send crafted requests to this endpoint, leveraging improper input handling to execute unwanted commands. The vulnerability flows across multiple components within the cups-browsed system, from how it handles network print requests to how it aggregates and interfaces with third-party printer definitions. Attacks succeed by exploiting the assumption of trustworthy input, granting unauthorized remote access upon successful execution. The vulnerability in question highlights the need for thorough checks and valid authentication mechanisms in network services to prevent unsanctioned resource manipulation.

If exploited, this vulnerability enables attackers to execute arbitrary code on the compromised server, potentially leading to full system control. The effects can range from data theft, unauthorized system configurations, or network disablement, imposing significant risks on both user data and network integrity. Exploiting this vulnerability could also expose sensitive configurations, enabling attackers to install backdoors or pivot to other internal network systems. The threat becomes significantly pronounced when the system under attack operates within public networks, exposing it to a wider range of attack vectors. Prevention efforts are crucial to maintain system security and shield against unauthorized external influences.

REFERENCES

• https://www.evilsocket.net/2024/09/26/Attacking-UNIX-systems-via-CUPS-Part-I/
• https://github.com/OpenPrinting/cups-browsed/security/advisories/GHSA-rj88-6mr5-rcw8
• https://github.com/OpenPrinting/cups-browsed/blob/master/daemon/cups-browsed.c#L13992
• https://github.com/OpenPrinting/cups-filters/security/advisories/GHSA-p9rh-jxmq-gq47
• https://github.com/OpenPrinting/libcupsfilters/security/advisories/GHSA-w63j-6g73-wmg5