CVE-2023-7207

What it actually does

Path traversal flaw in cpio allows crafted archives to write files outside the intended extraction directory when the --no-absolute-filenames option is used, due to an incomplete revert of prior patches.

Why it matters to the business

Systems relying on cpio for archive extraction face risk of unauthorized file placement or overwrite, potentially disrupting operations or enabling follow-on compromise; low exploit likelihood but affects core packaging tools across Linux distributions.

How an attack unfolds

An attacker creates a malicious archive containing directory traversal sequences in file paths, then tricks a target into extracting it using cpio with the --no-absolute-filenames flag, resulting in files being written to arbitrary filesystem locations.

How to fix it

Upgrade cpio to the fixed commit 376d663340a9dc91c91a5849e5713f07571c1628 or later; rebuild and redistribute packages containing cpio; audit and update any scripts or automation that invoke cpio extraction.

How to confirm the fix worked

Confirm cpio binary reports a version containing commit 376d663340a9dc91c91a5849e5713f07571c1628; test extraction of a crafted archive containing traversal paths to verify files remain confined to the target directory.

Typical attack path

1. Craft archive with relative paths containing ../ sequences
2. Deliver archive to target via download, email, or package repository
3. Induce extraction via cpio --no-absolute-filenames or equivalent script
4. Files are written outside target directory, enabling further actions such as config modification or binary replacement

How to detect it

Search system logs and process execution records for cpio invocations that include --no-absolute-filenames combined with archive sources from untrusted locations; monitor for unexpected file creation timestamps or paths outside expected extraction roots after archive operations.

What your security team should do

• Prioritize patching cpio in build pipelines and container images within 30 days given the long publication window
• Review and restrict use of --no-absolute-filenames in automated extraction workflows
• Add cpio version checks to software bill of materials and dependency scanners