CVE-2025-55188: 
7-Zip 脆弱性の分析と軽減

CVE-2025-55188 is a security vulnerability affecting 7-Zip versions prior to 25.01, discovered in August 2025. The vulnerability stems from improper handling of symbolic links during archive extraction, which could allow attackers to perform arbitrary file writes on target systems. The flaw affects both Linux and Windows systems, though Windows systems require additional conditions to be exploited (OSS Security, Help Net Security).

The vulnerability occurs when 7-Zip fails to properly validate symbolic links during the extraction of archive formats that support symbolic links, including ZIP, TAR, 7Z, and RAR files. The flaw has been assigned a CVSS score of 2.7 (AV:L/AC:H/PR:N/UI:R/S:C/C:N/I:L/A:N), though there is ongoing discussion about whether this score accurately reflects the vulnerability's severity. The issue primarily affects Linux systems, but can also impact Windows systems when the extraction process has symbolic link creation capabilities, such as Administrator privileges or Developer Mode enabled (OSS Security, GBHackers).

The vulnerability enables attackers to achieve arbitrary file write capabilities on affected systems, which could lead to unauthorized access and code execution. Attackers could potentially overwrite sensitive system files, including SSH keys, shell configuration files like .bashrc, or other critical system components. A single malicious archive extraction could trigger multiple exploitation attempts, allowing attackers several opportunities to write to sensitive file locations (OSS Security).

The vulnerability has been patched in 7-Zip version 25.01. The update includes changes to the code for handling symbolic links to provide greater security when extracting files from archives. Users can also use the command line switch -snld20 to bypass default security checks when creating symbolic links if necessary. Organizations and users are strongly advised to update to version 25.01 immediately (7-Zip Release).