[GestureBuildSprite Use-After-Free]

[XInput2 PassiveUngrabDevice Modifier Out-of-Bounds Write]

[RandR ChangeProviderProperty Heap Buffer Overflow]

.Org Server XInput Passive Grab Use-After-Free

A flaw was found in xorg-server. Querying or changing XKB button actions such as moving from a touchpad to a mouse can result in out-of-bounds memory reads and writes. This may allow local privilege escalation or possible remote code execution in cases where X11 forwarding is involved.

A vulnerability was found in X.Org. This security flaw occurs because the handler for the XIChangeProperty request has a length-validation issues, resulting in out-of-bounds memory reads and potential information disclosure. This issue can lead to local privileges elevation on systems where the X server is running privileged and remote code execution for ssh X forwarding sessions.

A vulnerability was found in X.Org. This security flaw occurs because the handler for the XIPassiveUngrab request accesses out-of-bounds memory when invoked with a high keycode or button code. This issue can lead to local privileges elevation on systems where the X server is running privileged and remote code execution for ssh X forwarding sessions.

A vulnerability was found in X.Org. This security flaw occurs because the handler for the ScreenSaverSetAttributes request may write to memory after it has been freed. This issue can lead to local privileges elevation on systems where the X server is running privileged and remote code execution for ssh X forwarding sessions.

A vulnerability was found in X.Org. This security flaw occurs becuase the swap handler for the XTestFakeInput request of the XTest extension may corrupt the stack if GenericEvents with lengths larger than 32 bytes are sent through a the XTestFakeInput request. This issue can lead to local privileges elevation on systems where the X server is running privileged and remote code execution for ssh X forwarding sessions. This issue does not affect systems where client and server use the same byte order.

A vulnerability, which was classified as problematic, was found in X.org Server. This affects an unknown part of the file hw/xquartz/X11Controller.m of the component xquartz. The manipulation leads to denial of service. It is recommended to apply a patch to fix this issue. The identifier VDB-211053 was assigned to this vulnerability.

A vulnerability, which was classified as problematic, has been found in X.org Server. Affected by this issue is the function ProcXkbGetKbdByName of the file xkb/xkb.c. The manipulation leads to memory leak. It is recommended to apply a patch to fix this issue. The identifier of this vulnerability is VDB-211052.

In X.Org X server 20.11 through 21.1.16, when a client application uses easystroke for mouse gestures, the main thread modifies various data structures used by the input thread without acquiring a lock, aka a race condition. In particular, AttachDevice in dix/devices.c does not acquire an input lock.

A vulnerability was found in X.Org. This security flaw occurs because the handler for the XvdiSelectVideoNotify request may write to memory after it has been freed. This issue can lead to local privileges elevation on systems where the X se

A vulnerability was found in X.Org. This security flaw occurs because the XkbCopyNames function left a dangling pointer to freed memory, resulting in out-of-bounds memory access on subsequent XkbGetKbdByName requests.. This issue can lead to local privileges elevation on systems where the X server is running privileged and remote code execution for ssh X forwarding sessions.

A flaw was found in the Xorg-x11-server. An out-of-bounds access issue can occur in the ProcXkbSetGeometry function due to improper validation of the request length.

A flaw was found in the Xorg-x11-server. The specific flaw exists within the handling of ProcXkbSetDeviceInfo requests. The issue results from the lack of proper validation of user-supplied data, which can result in a memory access past the end of an allocated buffer. This flaw allows an attacker to escalate privileges and execute arbitrary code in the context of root.

A vulnerability classified as critical was found in X.org Server. Affected by this vulnerability is the function GetCountedString of the file xkb/xkb.c. The manipulation leads to buffer overflow. It is recommended to apply a patch to fix this issue. The associated identifier of this vulnerability is VDB-211051.

glamorfontget() builds a per-font texture atlas by laying out every glyph in the font into a single backing buffer. It computes the slot dimensions from the font's declared maxbounds, but copies each per-glyph bitmap using the individual glyph's metrics (GLYPHHEIGHTPIXELS/GLYPHWIDTHBYTES macros). There is no check that maxbounds actually bounds the per-glyph values.

When the font is loaded from a malicious PCF file whose per-glyph metrics exceed the file's maxbounds, the per-glyph memcpy writes far beyond the heap-allocated slot, producing a heap buffer overflow with attacker-controlled extent and attacker-controlled content.

An authenticated X client can trigger this by using SetFontPath to add a directory containing a crafted PCF font, loading the font with OpenFont, and drawing text on a glamor-backed drawable. Only servers using the glamor acceleration backend (Xorg with modesetting driver, Xwayland) are affected.

CommonMakeCurrent() in the GLX dispatch layer captures a pointer into the per-client cl->contextTags array by calling GlxLookupContextTag(). This returns a direct pointer into an array later realloced. If realloc() moves the buffer to a new location, the previously captured oldTag pointer becomes dangling. The subsequent GlxFreeContextTag(oldTag) then writes zeros into freed heap memory (use-after-free). Five fields are zeroed at fixed offsets (16, 24, 32, 36, 40 bytes) within the stale slot. A malicious client can force the realloc by creating 16 GLX contexts with MakeCurrent(oldContextTag=0) to fill all tag slots to capacity, then issuing a 17th MakeCurrent with a non-zero oldContextTag. This triggers the realloc while oldTag points into the old buffer. The attack requires only 34 X11 requests (17 CreateContext + 17 MakeCurrent) from a single client.

[Glamor CopyArea CPU-FBO Heap Buffer Overflow]

A flaw was identified in the X.Org X server’s X Keyboard (Xkb) extension where improper bounds checking in the XkbSetCompatMap() function can cause an unsigned short overflow. If an attacker sends specially crafted input data, the value calculation may overflow, leading to memory corruption or a crash.

A flaw was discovered in the X.Org X server’s X Keyboard (Xkb) extension when handling client resource cleanup. The software frees certain data structures without properly detaching related resources, leading to a use-after-free condition. This can cause memory corruption or a crash when affected clients disconnect.

A flaw was found in the X.Org X server. This out-of-bounds read vulnerability in the XKB geometry processing, specifically within the CheckSetGeom() and XkbAddGeomKeyAlias functions, allows an attacker to read uninitialized or out-of-bounds memory. An attacker with a connection to the X11 server, either locally or remotely, can exploit this without user interaction. This could lead to the disclosure of memory contents or cause a denial of service by crashing the server.

A flaw was found in the X.Org X server. This vulnerability, an out-of-bounds read, affects the XKB (X Keyboard Extension) modifier map handling. An attacker with access to the X11 server can exploit this by sending a malformed request, which causes the server to read beyond its intended memory boundaries. This can lead to the exposure of sensitive information or cause the server to crash, resulting in a denial of service.

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 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.

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.

A flaw was found in the X server's request handling. Non-zero 'bytes to ignore' in a client's request can cause the server to skip processing another client's request, potentially leading to a denial of service.

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.

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.