Recently, the U.S. Cybersecurity and Infrastructure Security Agency (CISA) has discovered and added three critical vulnerabilities to its Known Exploited Vulnerabilities (KEV) catalog. These vulnerabilities, impacting North Grid Proself, ProjectSend, and Zyxel firewalls, are being actively exploited, posing serious risks of data breaches and operational disruptions to unpatched systems. At the time of publishing, Zyxel acknowledged the issue and advised users to update their firmware promptly and strengthen admin credentials.

Vulnerabilities Identified in North Grid Proself, ProjectSend, and Zyxel Firewalls

North Grid Proself Vulnerability (CVE-2023-45727): A severe XML processing vulnerability in North Grid Proself has been identified, allowing attackers to bypass restrictions and access sensitive server data. Systems running versions older than 5.62, 1.65, and 1.08 are vulnerable to exploitation through maliciously crafted XML requests, which can extract sensitive account information.

ProjectSend Vulnerability (CVE-2024-11680): A critical authentication flaw in ProjectSend, an open-source file-sharing platform, has been flagged with a CVSS severity score of 9.8. Versions prior to r1720 are susceptible to attacks where malicious actors manipulate the options.php file using crafted HTTP requests. This enables them to create unauthorized accounts, upload webshells, and inject harmful JavaScript code. Security researchers from VulnCheck report that attackers are leveraging automated tools such as Nuclei and Metasploit to exploit this vulnerability.

Notably, exploitation attempts are marked by altered server configurations, including random strings in landing page titles—a trend observed since September 2024. Despite a patch being released in May 2023, over 4,000 exposed instances remain vulnerable.

Zyxel Firewall Vulnerability (CVE-2024-11667): Zyxel firewalls running firmware versions between V5.00 and V5.38 are vulnerable to a directory traversal attack. This flaw allows attackers to upload or download files via manipulated URLs within the web management interface, potentially compromising system integrity.

Exploitation Attempts and Mitigation Strategies

ProjectSend instances have been the primary focus of attackers. Public-facing systems have seen unauthorized user registrations—a setting not enabled by default—facilitating access for malicious actors. Webshells uploaded during these attacks are often stored in predictable directories, with filenames tied to timestamps and user data. Organizations are urged to review server logs to identify and address suspicious activities.

Under Binding Operational Directive (BOD) 22-01, federal agencies must prioritize these vulnerabilities, while CISA has recommended that private organizations take immediate action to mitigate the risks. Updating software, reviewing server configurations, and enhancing log analysis are critical steps to safeguard systems from exploitation.