UBUNTU-CVE-2026-124744: Path Traversal
A flaw was found in BusyBox. When extracting files using the cpio utility with path traversal protection enabled, hardlink target paths are not properly sanitized. By tricking a user or automated process into extracting a crafted archive, an attacker can create hardlinks that point to files outside the intended extraction directory. This issue may allow an attacker to modify or overwrite arbitrary files outside the target directory during subsequent extraction operations.
Affected Software
Event History
Frequently Asked Questions
Who is exposed to this issue?
Systems that use BusyBox cpio to extract untrusted or attacker-supplied archives are exposed, including cases where extraction is performed by an automated process. The issue applies even when cpio path traversal protection is enabled.
What does an attacker need to exploit it?
An attacker needs to convince a user or automated process to extract a crafted cpio archive. The crafted archive uses hardlink target paths that bypass the expected sanitization.
What can happen after a crafted archive is extracted?
The archive can create hardlinks to files outside the intended extraction directory. During subsequent extraction operations, this may enable modification or overwriting of arbitrary files outside that directory.