MGASA-2021-0573

Updated x11-server packages fix security vulnerabilities:

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-2021-4008).

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-2021-4009).

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-2021-4010).

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 (CVE-2021-4011).

All of these 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.