The pathname canonicalization functionality in io/filesystem/filesystem.cc in Widelands before 15.1 expands leading ~ (tilde) characters to home-directory pathnames but does not restrict use of these characters in strings received from the network, which might allow remote attackers to conduct absolute path traversal attacks and overwrite arbitrary files via a ~ in a pathname that is used for a file transfer in an Internet game, a different vulnerability than CVE-2011-1932.