CVE-2015-1197

What it actually does

When cpio is invoked with --no-absolute-filenames, a symlink present inside an archive can be followed during extraction, allowing a local attacker to write to arbitrary filesystem locations outside the intended destination directory.

Why it matters to the business

Attackers with local access can overwrite configuration files, binaries, or data on affected systems, leading to integrity loss, potential privilege escalation, or disruption of services that rely on the extracted archive contents.

How an attack unfolds

An attacker prepares a cpio archive containing a symlink that points outside the extraction root, then convinces a privileged process or user to extract the archive using the --no-absolute-filenames flag; the extraction follows the symlink and writes attacker-controlled content to the target path.

How to fix it

Upgrade affected packages to the versions that contain a patched cpio implementation; for the listed Chainguard images this means argo-cd-2.9, argo-cd-2.9-compat and argo-cd-2.9-repo-server updated to 2.9.17-r1 or newer. Where direct cpio upgrades are available, move to a release that enforces safer path handling even under --no-absolute-filenames.

How to confirm the fix worked

Confirm the installed cpio binary reports a version newer than 2.11 or that the Chainguard package manifests show the 2.9.17-r1 (or later) digest; re-test extraction of a crafted archive containing symlinks to verify writes are confined to the intended directory.

Typical attack path

1. Craft a cpio archive embedding a malicious symlink entry
2. Place the archive in a location reachable by the target process or user
3. Trigger extraction via cpio --no-absolute-filenames (often through automated packaging or backup scripts)
4. Symlink is followed and arbitrary file is overwritten
5. Attacker leverages the modified file for persistence or escalation

How to detect it

Search process execution logs and audit trails for invocations of cpio or derived tools that include the --no-absolute-filenames flag; inspect extraction target directories for unexpected symlinks or files whose timestamps or owners differ from the archive metadata.

What your security team should do

• Immediately update the three listed Chainguard argo-cd images to 2.9.17-r1
• Audit all scripts and automation that invoke cpio with --no-absolute-filenames and replace with safer alternatives such as tar --no-overwrite-dir
• Add runtime detection for cpio processes writing through symlinks via filesystem monitoring
• Review historical extraction logs for unexpected file modifications outside designated paths