CVE-2025-56503 concerns a potential privilege escalation vulnerability in Sublime Text 4 build 4200, developed by Sublime HQ Pty Ltd. The issue reportedly allows an authenticated attacker with low-level privileges to escalate to Administrator by replacing the uninstall executable file within the installation directory with a malicious binary. This replacement could enable the attacker to execute code with elevated privileges during uninstallation or related operations. The vulnerability is categorized under CWE-266, indicating improper privilege management. The CVSS v3.1 base score is 6.5, with an attack vector of network (remote), low attack complexity, requiring privileges but no user interaction, and impacting confidentiality but not integrity or availability. However, the vendor disputes the vulnerability's validity, arguing that replacing the uninstall file necessitates administrator-level permissions, which would prevent low-privileged users from exploiting this vector. No patches or fixes have been released, and no active exploitation has been observed. The vulnerability highlights the importance of secure file permission configurations on software installation directories to prevent unauthorized modifications. Organizations using Sublime Text 4 should verify their permission settings and monitor for suspicious file changes to mitigate potential risks.

If exploitable, this vulnerability could allow an attacker with low-level authenticated access to escalate privileges to Administrator, potentially compromising the entire system. This would enable unauthorized access to sensitive data, installation of persistent malware, and full control over the affected machines. For European organizations, especially those in software development, IT services, and critical infrastructure sectors using Sublime Text 4, the impact could include data breaches, operational disruption, and reputational damage. However, since the vendor disputes the exploitability due to required administrator permissions for file replacement, the practical impact may be limited to misconfigured environments where users have excessive write permissions. The lack of known exploits reduces immediate risk but does not eliminate the threat, particularly in environments with lax privilege separation. The vulnerability primarily threatens confidentiality due to potential unauthorized data access but does not directly affect integrity or availability. The medium CVSS score reflects this moderate risk level.

1. Restrict write permissions on Sublime Text installation directories to Administrator accounts only, preventing low-privileged users from modifying uninstall files or other executables. 2. Implement strict access control policies and regularly audit file system permissions on developer workstations and servers. 3. Employ file integrity monitoring tools to detect unauthorized changes to critical application files, including uninstallers. 4. Educate users and administrators about the risks of privilege escalation and the importance of least privilege principles. 5. Isolate development environments where possible to limit the impact of potential exploits. 6. Monitor vendor communications for any patches or updates addressing this vulnerability and apply them promptly. 7. Consider application whitelisting to prevent execution of unauthorized binaries. 8. Review and harden endpoint security configurations to detect and block suspicious activities related to privilege escalation attempts.