OSC is the command line tool and API for the Open Build Service.
A vulnerability has been discovered that may allow remote attackers to execute arbitrary commands via shell metacharacters in a _service file.
A remote attacker could possibly execute arbitrary code with the privileges of the process.
There is no known work around at this time.
All OSC users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=dev-util/osc-0.152.0"