LinPopUp is a graphical application that acts as a frontend to Samba client messaging functions, allowing a Linux desktop to communicate with a Microsoft Windows computer that runs Winpopup.
Stephen Dranger discovered that LinPopUp contains a buffer overflow in string.c, triggered when replying to a remote user message.
A remote attacker could craft a malicious message that, when replied using LinPopUp, would exploit the buffer overflow. This would result in the execution of arbitrary code with the privileges of the user running LinPopUp.
There is no known workaround at this time.
All LinPopUp users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=net-im/linpopup-2.0.4-r1"