Attack Chain

1. An attacker crafts a malicious path using directory traversal sequences (e.g., ../) designed to escape the intended file system boundaries.
2. The application using go-billy receives the crafted path, intending to access a file within a restricted directory.
3. The application calls go-billy functions (e.g., Open, ReadFile, Stat) to interact with the file system using the attacker-controlled path.
4. Due to insufficient sanitization within the vulnerable osfs.ChrootOS implementation, the traversal sequences are not properly resolved or blocked.
5. go-billy’s file system access functions resolve the path, allowing the attacker to navigate outside the intended directory and access sensitive files or directories.
6. The application reads or modifies files outside the intended scope, leading to potential information disclosure or arbitrary file manipulation.
7. The attacker gains unauthorized access to sensitive data or system resources.
8. The attacker may further exploit the compromised system to achieve lateral movement or other malicious objectives.

Impact

Successful exploitation of these path traversal vulnerabilities can lead to unauthorized access to sensitive files and directories, potentially resulting in information disclosure or arbitrary file manipulation. The number of victims and targeted sectors depend on the specific applications using the vulnerable go-billy library. If the attack succeeds, attackers can bypass intended security boundaries, read configuration files, or even modify critical system files, leading to complete system compromise.

Recommendation

• Upgrade to go-billy version 6 or later to leverage the more secure os.Root implementation for osfs to prevent CVE-2026-44973.
• Migrate away from osfs.ChrootOS and use osfs.BoundOS instead, as osfs.ChrootOS is deprecated and vulnerable as noted in the overview.
• Enable process creation logging on affected systems to facilitate detection of suspicious file access patterns.