Arbitrary file overwrite via predictable log symlinks

Insecure log-file creation in Google glog before 1.2.4 allows local users to overwrite sensitive files through planted symlinks. The createInDir path generates predictable names in a widely writable log directory and previously used os.Create, which follows an attacker-planted symlink and truncates its target. Exploitation requires a privileged glog-using process to create the predicted filename after an unprivileged local user plants the link; the consequence is arbitrary file overwrite with that process's rights.