Trivial Bug in X.Org Gives Root Permission on Linux and BSD Systems

Trivial Bug in X.Org Gives Root Permission on Linux and BSD Systems


An advisory on Thursday describes the problem as an “incorrect command-line parameter validation” that also allows an attacker to overwrite arbitrary files.
Privilege escalation can be accomplished via the -modulepath argument by setting an insecure path to modules loaded by the server. Arbitrary file overwrite is possible through the -logfile argument, because of improper verification when parsing the option.
OpenBSD, the free and open-source operating system with a strong focus on security, uses xorg. On October 18, the project released version 6.4 of the OS, affected by CVE-2018-14665. This could have been avoided, though.
Theo de Raadt, founder and leader of the OpenBSD project, says that X maintainer knew about the problem since at least October 11. For some reason, the OpenBSD developers received the message one hour before the public announcement this Thursday, a week after their new OS release.
“As yet we don’t have answers about why our X maintainer (on the X security team) and his team provided information to other projects (some who don’t even ship with this new X server) but chose to not give us a heads-up which could have saved all the new 6.4 users a lot of grief,” Raadt says.
Had OpenBSD developers known about the bug before the release, they could have taken steps to mitigate the problem or delay the launch for a week or two.
To remedy the problem, the OpenBSD project provides a source code patch, which requires compiling and rebuilding the X server.

submitted by: Arnfried Walbrecht


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