CVE-2015-3418

The ProcPutImage function in dix/dispatch.c in X.Org Server (aka xserver and xorg-server) before 1.16.4 allows attackers to cause a denial of service (divide-by-zero and crash) via a zero-height PutImage request.

The ProcPutImage function in dix/dispatch.c in X.Org Server (aka xserver and xorg-server) before 1.16.4 allows attackers to cause a denial of service (divide-by-zero and crash) via a zero-height PutImage request.

Updated x11-server packages fix security vulnerability:

A regression in the fix for CVE-2014-8092 (MGASA-2014-0532) caused another issue which could lead to a local denial of service (CVE-2015-3418).

This collective update for xorg-x11-server provides the following fixes:

* Fix a segmentation fault that can occur when X11 packets are
  forwarded between a client and a server with different endianess.
  (bnc#874903)
* Free software cursor backing pixmap when transition between screens.
  This fixes a crash in multi screen support when an assert gets hit.
  (bnc#880835)
* Ignore numlock in Xvnc. Following keys from VNC client will be
  already modulated by numlock on client side. (bnc#878446)
* Fix crash when Xinerama gets disabled after RanR12 is initialized.
  (bnc#878433)
* Prevent crash at the end of 2nd server generation when number of
  privates differ between 1st and 2nd. (bnc#883598)
* Move Xinerama disable when only one screen is present to main loop.
  (bnc#883598)
* Improve Xinerama command line option handling. (bnc#883598)
* Work around a possible crash when object belongs to a client that no
  longer exists. (bnc#883516)
* Try to make keyboard bell ring on all devices attached to master
  keyboard. (bnc#879019)
* Implement DeleteInputDeviceRequest in Xvnc to avoid server crash when
  the Xserver restarts after a server reset. (bnc#880745).

This collective update for xorg-x11-server provides the following fixes:

* Fix a segmentation fault that can occur when X11 packets are
  forwarded between a client and a server with different endianess.
  (bnc#874903)
* Free software cursor backing pixmap when transition between screens.
  This fixes a crash in multi screen support when an assert gets hit.
  (bnc#880835)
* Ignore numlock in Xvnc. Following keys from VNC client will be
  already modulated by numlock on client side. (bnc#878446)
* Fix crash when Xinerama gets disabled after RanR12 is initialized.
  (bnc#878433)
* Prevent crash at the end of 2nd server generation when number of
  privates differ between 1st and 2nd. (bnc#883598)
* Move Xinerama disable when only one screen is present to main loop.
  (bnc#883598)
* Improve Xinerama command line option handling. (bnc#883598)
* Work around a possible crash when object belongs to a client that no
  longer exists. (bnc#883516)
* Try to make keyboard bell ring on all devices attached to master
  keyboard. (bnc#879019)
* Implement DeleteInputDeviceRequest in Xvnc to avoid server crash when
  the Xserver restarts after a server reset. (bnc#880745).

The X Server was updated to fix 1 security issues and 4 bugs:

Security issues:

• CVE-2015-3418: Fixed a regression introduced by CVE-2014-8092 in PutImage that caused crashes when called with 0 height (bnc#928520).

Bugs fixed:

• Xephyr: Don't crash when no command line argument is specified The DDX specific command line parsing function only gets called if command line arguments are present. Therefore this function is not suitable to initialize mandatory global variables. Replace main() instead. (bnc#925022)
• Xephyr: Print default server display number if none is specified (bnc#925022)
• Xephyr: Fix broken image when endianess of client machine and host-Xserver differ The image is created in the native byte order of the machine Xephyr is rendered on however drawn in the image byte order of the Xephyr server. Correct byte order in the xcb_image_t structure and convert to native before updating the window. If depths of Xephyr and host server differ this is already taken care of by the depth conversion routine. (bnc#923229).
• Xephyr: Fix compile when debugging is enabled (bnc#925021)
• Xephyr: Fix screen image draw for the non-Glamor & non-XHSM case xcb_image_put() prints the entire image, therefore don't use an offset. (bnc#925019)