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Altoid

Member

Registered: 2017-05-07

Posts: 1,432  

X.Org Security Advisory

Hello:

Just got this in my mailbox, good to see things are working as they should:

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X.Org Security Advisory: December 14, 2021

Multiple input validation failures in X server extensions
=========================================================

All of the following issues can lead to local privileges elevation on
systems where the X server is running privileged and remote code
execution for ssh X forwarding sessions.

* CVE-2021-4008/ZDI-CAN-14192 SProcRenderCompositeGlyphs out-of-bounds
access

The handler for the CompositeGlyphs request of the Render extension does
not properly validate the request length leading to out of bounds memory
write.

* CVE-2021-4009/ZDI-CAN 14950 SProcXFixesCreatePointerBarrier
out-of-bounds access

The handler for the CreatePointerBarrier request of the XFixes extension
does not properly validate the request length leading to out of bounds
memory write.

* CVE-2021-4010/ZDI-CAN-14951 SProcScreenSaverSuspend out-of-bounds access

The handler for the Suspend request of the Screen Saver extension does
not properly validate the request length leading to out of bounds memory
write.

* CVE-2021-4011/ZDI-CAN-14952 SwapCreateRegister out-of-bounds access

The handlers for the RecordCreateContext and RecordRegisterClients
requests of the Record extension do not properly validate the request
length leading to out of bounds memory write.

Patches
-------

Patches for this issues have been commited to the xorg server git
repository (https://gitlab.freedesktop.org/xorg/xserver). xorg-server
21.1.2 will be released shortly and will include these patches.

commit ebce7e2d80e7c80e1dda60f2f0bc886f1106ba60

    render: Fix out of bounds access in SProcRenderCompositeGlyphs()

    ZDI-CAN-14192, CVE-2021-4008

    This vulnerability was discovered and the fix was suggested by:
    Jan-Niklas Sohn working with Trend Micro Zero Day Initiative

commit b5196750099ae6ae582e1f46bd0a6dad29550e02

    xfixes: Fix out of bounds access in *ProcXFixesCreatePointerBarrier()

    ZDI-CAN-14950, CVE-2021-4009

    This vulnerability was discovered and the fix was suggested by:
    Jan-Niklas Sohn working with Trend Micro Zero Day Initiative

commit 6c4c53010772e3cb4cb8acd54950c8eec9c00d21

    Xext: Fix out of bounds access in SProcScreenSaverSuspend()

    ZDI-CAN-14951, CVE-2021-4010

    This vulnerability was discovered and the fix was suggested by:
    Jan-Niklas Sohn working with Trend Micro Zero Day Initiative

commit e56f61c79fc3cee26d83cda0f84ae56d5979f768

    record: Fix out of bounds access in SwapCreateRegister()

    ZDI-CAN-14952, CVE-2021-4011

    This vulnerability was discovered and the fix was suggested by:
    Jan-Niklas Sohn working with Trend Micro Zero Day Initiative

Thanks
======

This vulnerability was discovered by Jan-Niklas Sohn working with
Trend Micro Zero Day Initiative.

--
Povilas Kanapickas

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Best,

A.

Head_on_a_Stick

Member

From: London

Registered: 2019-03-24

Posts: 3,125  

Website

Re: X.Org Security Advisory

Thanks for the heads-up Altoid.

Just for the record:

on systems where the X server is running privileged

^ This does not apply to any Devuan beowulf (or later) systems that use startx to launch the desktop (or GDM but I don't think that's very popular here).

EDIT: posted from Wayland

Last edited by Head_on_a_Stick (2021-12-14 16:13:56)

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Brianna Ghey — Rest In Power

Altoid

Member

Registered: 2017-05-07

Posts: 1,432  

Re: X.Org Security Advisory

Hello:

Thanks for the heads-up ...

You're welcome.

on systems where the X server is running privileged

... does not apply to any Devuan beowulf (or later) systems that use startx ...

I'm still using SLiM which I'm happy to see made it into /merged chimaera/main amd64.

... posted from Wayland

Whatever rocks your boat desktop.  =^)

Best,

A.