Attack Chain

1. The attacker crafts a malicious link containing shell metacharacters and command substitutions within user-controlled parameters.
2. The attacker delivers the crafted link to a user with access to the Cockpit system logs UI, possibly through phishing or social engineering.
3. The user clicks on the malicious link, which is processed by the Cockpit system logs UI.
4. The Cockpit application fails to properly sanitize the user-controlled parameters within the link.
5. The unsanitized parameters are passed to a system command.
6. The injected shell metacharacters and command substitutions are interpreted by the shell.
7. Arbitrary shell commands are executed on the host system with the privileges of the Cockpit process.
8. The attacker gains control of the system and can perform actions such as installing malware, exfiltrating data, or disrupting services.

Impact

Successful exploitation of CVE-2026-4802 allows a remote attacker to achieve arbitrary command execution on the host system. This can lead to a complete system compromise, potentially affecting all data and services hosted on the system. The lack of sanitization can allow an attacker to perform any action that the compromised Cockpit instance can, including installing malicious software, creating new user accounts, or accessing sensitive data.

Recommendation

• Apply available patches for Cockpit from Red Hat to remediate CVE-2026-4802.
• Deploy the Sigma rule “Detect CVE-2026-4802 Exploitation Attempt via Crafted URL” to identify potential exploitation attempts in webserver logs.
• Implement strict input validation and sanitization for all user-supplied parameters within Cockpit’s system logs UI.
• Regularly review and audit Cockpit logs for suspicious activity or unauthorized access.