Velero, an open‑source tool for backing up and restoring Kubernetes resources, contains a file path traversal flaw in versions prior to 1.18.1. When restoring a backup, the tar extraction code does not correctly sanitize parent directory references. An attacker who can supply a malicious backup to the storage backend can embed paths that escape the intended extraction directory, overwriting arbitrary files in the Velero pod. This allows the attacker to alter configuration or executable files, creating the potential for privilege escalation or denial of service. The weakness is a classic instance of path traversal as described by CWE‑22.

The vulnerability affects Velero versions before 1.18.1, specifically the Velero backup/restore tool provided by velero‑io:velero. Any deployment using these versions of the backup component is susceptible unless the backup storage is protected from unauthorized writes.

The CVSS score of 5.9 classifies the issue as medium severity. The exploitability relies on an attacker having write access to the backup storage and initiating a restore, conditions that are typically restricted to privileged users. EPSS data is unavailable, and the vulnerability is not listed in CISA’s KEV catalog, suggesting limited reported exploitation. Nonetheless, if the storage is compromised, the path traversal can overwrite sensitive files, posing a moderate risk to the integrity of the Velero environment.