Technical impact
Rclone prior to 1.75.2 contains a path traversal flaw in the local backend's translateLink function that trims the .rclonelink suffix after a containment check. This allows an attacker to craft a directory named …rclonelink in a source tree that is synced with the --links and --metadata options, causing files to resolve outside the intended destination root and enabling unauthorized changes to the destination's parent directory ownership, timestamps, and extended attributes.
Affected Systems
Vendors and products affected are rclone, specifically all releases before version 1.75.2. Users of rclone 1.75.1 or earlier who use the local backend with --links and --metadata are at risk.
Risk and Exploitability
The CVSS score of 7 indicates a high severity vulnerability. The EPSS score is not available, and the flaw is not listed in CISA KEV, suggesting no widespread exploits have been reported. However, exploitation requires an attacker to supply a specially crafted source tree containing a …rclonelink directory and to run rclone with --links and --metadata, which many users perform when syncing data. Successful exploitation could lead to privilege escalation by altering ownership and metadata of parent directories within the destination.