Xorg: xwayland: use-after-free in syncinittrigger()
A use-after-free flaw was found in X.Org and Xwayland. When changing an alarm, the values of the change mask are evaluated one after the other, changing the trigger values as requested, and eventually, SyncInitTrigger() is called. If one of the changes triggers an error, the function will return early, not adding the new sync object, possibly causing a use-after-free when the alarm eventually triggers.
Xorg: xwayland: use-after-free in playreleasedevents()
A use-after-free flaw was found in X.Org and Xwayland. When a device is removed while still frozen, the events queued for that device remain while the device is freed. Replaying the events will cause a use-after-free.
Xorg: xwayland: use of uninitialized pointer in compredirectwindow()
An access to an uninitialized pointer flaw was found in X.Org and Xwayland. The function compCheckRedirect() may fail if it cannot allocate the backing pixmap. In that case, compRedirectWindow() will return a BadAlloc error without validating the window tree marked just before, which leaves the validated data partly initialized and the use of an uninitialized pointer later.
Xorg: xwayland: out-of-bounds write in createpointerbarrierclient()
An out-of-bounds write flaw was found in X.Org and Xwayland. The function GetBarrierDevice() searches for the pointer device based on its device ID and returns the matching value, or supposedly NULL, if no match was found. However, the code will return the last element of the list if no matching device ID is found, which can lead to out-of-bounds memory access.
Xorg: xwayland: buffer overflow in xkbchangetypesofkey()
A buffer overflow flaw was found in X.Org and Xwayland. If XkbChangeTypesOfKey() is called with a 0 group, it will resize the key symbols table to 0 but leave the key actions unchanged. If the same function is later called with a non-zero value of groups, this will cause a buffer overflow because the key actions are of the wrong size.
Xorg: xwayland: heap overflow in xkbwritekeysyms()
A heap overflow flaw was found in X.Org and Xwayland. The computation of the length in XkbSizeKeySyms() differs from what is written in XkbWriteKeySyms(), which may lead to a heap-based buffer overflow.
Xorg: xwayland: buffer overflow in xkbvmodmasktext()
A buffer overflow flaw was found in X.Org and Xwayland. The code in XkbVModMaskText() allocates a fixed-sized buffer on the stack and copies the names of the virtual modifiers to that buffer. The code fails to check the bounds of the buffer and would copy the data regardless of the size.
X.org: xwayland: use-after-free of the root cursor
A use-after-free flaw was found in X.Org and Xwayland. The root cursor is referenced in the X server as a global variable. If a client frees the root cursor, the internal reference points to freed memory and causes a use-after-free.
A flaw was found in the X.org server. Due to improperly tracked allocation size in _XkbSetCompatMap, a local attacker may be able to trigger a buffer overflow condition via a specially crafted payload, leading to denial of service or local privilege escalation in distributions where the X.org server is run with root privileges.
Xorg-x11-server: use-after-free in procrenderaddglyphs
A use-after-free vulnerability was found in the ProcRenderAddGlyphs() function of Xorg servers. This issue occurs when AllocateGlyph() is called to store new glyphs sent by the client to the X server, potentially resulting in multiple entries pointing to the same non-refcounted glyphs. Consequently, ProcRenderAddGlyphs() may free a glyph, leading to a use-after-free scenario when the same glyph pointer is subsequently accessed. This flaw allows an authenticated attacker to execute arbitrary code on the system by sending a specially crafted request.
Xorg-x11-server: heap buffer overread/data leakage in procappledricreatepixmap
A heap-based buffer over-read vulnerability was found in the X.org server's ProcAppleDRICreatePixmap() function. This issue occurs when byte-swapped length values are used in replies, potentially leading to memory leakage and segmentation faults, particularly when triggered by a client with a different endianness. This vulnerability could be exploited by an attacker to cause the X server to read heap memory values and then transmit them back to the client until encountering an unmapped page, resulting in a crash. Despite the attacker's inability to control the specific memory copied into the replies, the small length values typically stored i
Xorg-x11-server: heap buffer overread/data leakage in procxipassivegrabdevice
A heap-based buffer over-read vulnerability was found in the X.org server's ProcXIPassiveGrabDevice() function. This issue occurs when byte-swapped length values are used in replies, potentially leading to memory leakage and segmentation faults, particularly when triggered by a client with a different endianness. This vulnerability could be exploited by an attacker to cause the X server to read heap memory values and then transmit them back to the client until encountering an unmapped page, resulting in a crash. Despite the attacker's inability to control the specific memory copied into the replies, the small length values typically stored in
Xorg-x11-server: heap buffer overread/data leakage in procxigetselectedevents
A heap-based buffer over-read vulnerability was found in the X.org server's ProcXIGetSelectedEvents() function. This issue occurs when byte-swapped length values are used in replies, potentially leading to memory leakage and segmentation faults, particularly when triggered by a client with a different endianness. This vulnerability could be exploited by an attacker to cause the X server to read heap memory values and then transmit them back to the client until encountering an unmapped page, resulting in a crash. Despite the attacker's inability to control the specific memory copied into the replies, the small length values typically stored in
Xorg-x11-server: heap buffer overflow in disabledevice
A heap buffer overflow flaw was found in the DisableDevice function in the X.Org server. This issue may lead to an application crash or, in some circumstances, remote code execution in SSH X11 forwarding environments.
Xorg-x11-server: heap buffer overflow in xisenddevicehierarchyevent
A flaw was found in X.Org server. In the XISendDeviceHierarchyEvent function, it is possible to exceed the allocated array length when certain new device IDs are added to the xXIHierarchyInfo struct. This can trigger a heap buffer overflow condition, which may lead to an application crash or remote code execution in SSH X11 forwarding environments.
Xorg-x11-server: reattaching to different master device may lead to out-of-bounds memory access
An out-of-bounds memory access flaw was found in the X.Org server. This issue can be triggered when a device frozen by a sync grab is reattached to a different master device. This issue may lead to an application crash, local privilege escalation (if the server runs with extended privileges), or remote code execution in SSH X11 forwarding environments.
USN-6587-1 fixed vulnerabilities in X.Org X Server. The fix was incomplete
resulting in a possible regression. This update fixes the problem.
We apologize for the inconvenience.
Original advisory details:
Jan-Niklas Sohn discovered that the X.Org X Server incorrectly handled
memory when processing the DeviceFocusEvent and ProcXIQueryPointer APIs. An
attacker could possibly use this issue to cause the X Server to crash,
obtain sensitive information, or execute arbitrary code. (CVE-2023-6816)
Jan-Niklas Sohn discovered that the X.Org X Server incorrectly handled
reattaching to a different master device. An attacker could use this iss
A flaw was found in the X.Org server. The cursor code in both Xephyr and Xwayland uses the wrong type of private at creation. It uses the cursor bits type with the cursor as private, and when initiating the cursor, that overwrites the XSELINUX context.
A flaw was found in the X.Org server. The GLX PBuffer code does not call the XACE hook when creating the buffer, leaving it unlabeled. When the client issues another request to access that resource (as with a GetGeometry) or when it creates another resource that needs to access that buffer, such as a GC, the XSELINUX code will try to use an object that was never labeled and crash because the SID is NULL.
Xorg-x11-server: heap buffer overflow in devicefocusevent and procxiquerypointer
A flaw was found in X.Org server. Both DeviceFocusEvent and the XIQueryPointer reply contain a bit for each logical button currently down. Buttons can be arbitrarily mapped to any value up to 255, but the X.Org Server was only allocating space for the device's particular number of buttons, leading to a heap overflow if a bigger value was used.