UnAce is an utility to extract, view and test the contents of an ACE archive.
Ulf Harnhammar discovered that UnAce suffers from buffer overflows when testing, unpacking or listing specially crafted ACE archives (CAN-2005-0160). He also found out that UnAce is vulnerable to directory traversal attacks, if an archive contains “./..” sequences or absolute filenames (CAN-2005-0161).
An attacker could exploit the buffer overflows to execute malicious code or the directory traversals to overwrite arbitrary files.
There is no known workaround at this time.
All UnAce users should upgrade to the latest available version:
# emerge --sync # emerge --ask --oneshot --verbose ">=app-arch/unace-2.5-r3"