Description
A logic error in the ln utility of uutils coreutils allows the utility to dereference a symbolic link target even when the --no-dereference (or -n) flag is explicitly provided. The implementation previously only honored the "no-dereference" intent if the --force (overwrite) mode was also enabled. This flaw causes ln to follow a symbolic link that points to a directory and create new links inside that target directory instead of treating the symbolic link itself as the destination. In environments where a privileged user or system script uses ln -n to update a symlink, a local attacker could manipulate existing symbolic links to redirect file creation into sensitive directories, potentially leading to unauthorized file creation or system misconfiguration.
Problem types
CWE-61: UNIX Symbolic Link (Symlink) Following
Product status
Any version before 0.8.0
Credits
Zellic
References
github.com/uutils/coreutils/pull/11253
github.com/uutils/coreutils/releases/tag/0.8.0