Fysa – critical RCE flaw in GNU-Linux systems

The first of a series of blog posts has been published detailing a vulnerability in the Common Unix Printing System (CUPS), which purportedly allows attackers to gain remote access to UNIX-based systems. The vulnerability, which affects various UNIX-based operating systems, can be exploited by sending a specially crafted HTTP request to the CUPS service.

• Threat Type: Remote code execution vulnerability in CUPS service
• Industries Impacted: UNIX-based systems across various industries, including but not limited to, finance, healthcare, and government
• Geolocation: Global, with potential impact on UNIX-based systems worldwide
• Environment Impact: High severity, allowing attackers to gain remote access and execute arbitrary code on vulnerable systems

X-Force Incident Command is monitoring what claims to be the first in a series of blog posts from security researcher, Simone Margaritelli, detailing a vulnerability in the Common Unix Printing System (CUPS), which purportedly can be exploited by sending a specially crafted HTTP request to the CUPS service. The vulnerability affects various UNIX-based operating systems, including but not limited to, Linux and macOS. The vulnerability can be exploited to gain remote access to affected systems, allowing attackers to execute arbitrary code and potentially gain elevated privileges. X-Force is investigating the disclosure and monitoring for exploitation. We will continue to monitor this situation and provide updates as available.

• The vulnerability affects various UNIX-based operating systems, including but not limited to, Linux and macOS
• All versions of Red Hat Enterprise Linux (RHEL) are affected, but are not vulnerable in their default configurations.
• The vulnerability can be exploited by sending a specially crafted HTTP request to the CUPS service
• The vulnerability allows attackers to gain remote access to affected systems and execute arbitrary code
• The vulnerability has been identified as high severity, with potential for significant impact on affected organizations

• Disable the CUPS service or restrict access to the CUPS web interface
• In case your system can’t be updated and you rely on this service, block all traffic to UDP port 631 and possibly all DNS-SD traffic (does not apply to zeroconf)
• Implement additional security measures, such as network segmentation and access controls, to limit the spread of the vulnerability
• Conduct thorough vulnerability assessments and penetration testing to identify and remediate any other potential vulnerabilities
• Implement robust incident response and disaster recovery plans to mitigate the impact of a potential breach

• CVE-2024-47176 (Reserved)
• CVE-2024-47076 (Reserved)
• CVE-2024-47175 (Reserved)
• CVE-2024-47177 (Reserved)