HylaFAX 6.0.6 and HylaFAX+ 5.6.0 allow remote attackers to execute arbitrary code via a dial-in session that provides a FAX page with the JPEG bit enabled, which is mishandled in FaxModem::writeECMData() in the faxd/CopyQuality.c++ file.

In HylaFAX+ through 7.0.2 and HylaFAX Enterprise, the faxsetup utility calls chown on files in user-owned directories. By winning a race, a local attacker could use this to escalate his privileges to root.

HylaFAX+ through 7.0.2 and HylaFAX Enterprise have scripts that execute binaries from directories writable by unprivileged users (e.g., locations under /var/spool/hylafax that are writable by the uucp account). This allows these users to execute code in the context of the user calling these binaries (often root).