CVE-2025-27613 is an OS command injection vulnerability classified under CWE-78, affecting the j6t gitk tool, a graphical Git history browser implemented in Tcl/Tk. The vulnerability arises when a user clones an untrusted Git repository and runs gitk without additional command-line arguments. Specifically, if the 'Support per-file encoding' option is enabled in gitk's preferences (disabled by default), or if the user activates the 'Show origin of this line' feature in the main window, gitk may create or truncate files for which the user has write permissions. This behavior stems from improper neutralization of special elements in OS commands, allowing an attacker to influence file operations on the host system. The affected versions span from 1.7.0 up to multiple incremental patched versions before 2.50.1, with fixes released in versions 2.43.7, 2.44.4, 2.45.4, 2.46.4, 2.47.3, 2.48.2, 2.49.1, and 2.50.1. The vulnerability requires local user interaction and no privileges, limiting its exploitation scope. The CVSS 3.1 vector (AV:L/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N) indicates low attack complexity, no privileges required, user interaction needed, and a scope change due to the potential impact on other components. The impact is limited to integrity, with no confidentiality or availability loss. No known exploits have been reported in the wild as of the publication date.

For European organizations, the primary impact of CVE-2025-27613 lies in the potential unauthorized modification or truncation of files by users running vulnerable gitk versions on their local machines. This could lead to data integrity issues, especially in development environments where gitk is used to browse and analyze Git repositories. While the vulnerability does not directly compromise confidentiality or availability, the ability to alter files could facilitate further attacks or disrupt development workflows. Organizations relying on gitk for code review or repository analysis may face risks if untrusted repositories are cloned and the vulnerable features are enabled or used. The low CVSS score and requirement for user interaction reduce the likelihood of widespread exploitation, but insider threats or social engineering could increase risk. European entities with stringent data integrity requirements or regulatory obligations should consider this vulnerability significant enough to warrant prompt remediation.

To mitigate CVE-2025-27613, European organizations should: 1) Upgrade gitk installations to the latest patched versions (2.43.7 or later as specified) to eliminate the vulnerability. 2) Disable the 'Support per-file encoding' option in gitk preferences unless absolutely necessary, as it is disabled by default and its activation contributes to the vulnerability. 3) Avoid using the 'Show origin of this line' feature until patched versions are deployed. 4) Educate developers and users about the risks of cloning untrusted repositories and exercising caution when interacting with repository visualization tools. 5) Implement endpoint security controls to monitor and restrict unauthorized file modifications initiated by user applications. 6) Employ application whitelisting or sandboxing for gitk to limit its ability to affect critical files. 7) Regularly audit development environments for outdated gitk versions and enforce update policies. These steps go beyond generic advice by focusing on configuration management, user awareness, and environment hardening specific to gitk usage.