Pyload ng: pyLoad: Tar extraction creates device nodes and FIFOs (member types not filtered; tarfile extractall without filter=)

The UnTar extractor in pyLoad-ng does not check tar archive member types during extraction, only validating member names and symlink/hardlink targets. It calls tarfile.extractall without a filter= argument, which on Python versions below 3.14 defaults to fully trusted extraction. This allows crafted tar archives containing character device nodes or FIFOs to be created on disk. When pyLoad runs as root, this can lead to creation of device nodes granting raw disk access, resulting in full host compromise. The vulnerability is exploitable by any low-privileged user who can trigger archive extraction via the API. The issue extends a prior fix (GHSA-mvwx-582f-56r7) that addressed path traversal and link validation but did not cover member types. The recommended remediation is to reject or skip any archive members that are not regular files, directories, or safe links, and to use the filter="data" argument in extractall on Python 3.12+, or backport equivalent checks for older versions.

An attacker able to supply a crafted tar archive to pyLoad-ng running as root can cause the creation of arbitrary device nodes (character/block devices) and FIFOs on the host filesystem. This can lead to raw disk access and full host compromise. Even non-root deployments can have FIFOs and device nodes created in user-accessible directories, potentially causing denial of service or IPC confusion. The vulnerability is reachable by any low-privileged user who can invoke the archive extraction API.

No official patch or fix is explicitly stated in the provided data. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. In the meantime, it is recommended to modify the UnTar extractor to reject or skip any tar archive members that are device nodes or FIFOs by checking member types before extraction. Additionally, use the filter="data" argument with tarfile.extractall on Python 3.12 or later to restrict extraction to safe member types. Apply the same member-type validation in pre-extraction validation routines to ensure all extractors share this protection. Avoid running pyLoad-ng as root to reduce impact.