The XkbSetCompatMap() function attempts to resize the syminterpret buffer. However, it didn't update its size properly. It updated numsi only, without sizesi: https://gitlab.freedesktop.org/xorg/xserver/-/blob/cdb4d5648a818a8e8ab282341be37109589229ab/xkb/xkb.c#L2998

The exploit uses bitmap to achieve the arbitrary read and write. It leads to LPE for some distributions (xorg in debian xfce is run as root under specific display driver) and RCE for ssh x11 forwarding environment.

The exploit doesn't work if the OS installed on vmware and default virtualbox. It works on virtualbox with VBoxVGA graphic controller.

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.

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.

CVE-2023-0494/ZDI-CAN-19596: X.Org Server DeepCopyPointerClasses use-after-free

A dangling pointer in DeepCopyPointerClasses can be exploited by ProcXkbSetDeviceInfo() and ProcXkbGetDeviceInfo() to read/write into freed memory.

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 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 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 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 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 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, 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.

Reference: https://vuldb.com/?id.211052

Upstream patch: https://cgit.freedesktop.org/xorg/xserver/commit/?id=18f91b950e22c2a342a4fbc55e9ddf7534a707d2

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.

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.

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 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 xorg-x11-server in versions before 21.1.2 and before 1.20.14. An out-of-bounds access can occur in the SProcRenderCompositeGlyphs function. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

A flaw was found in xorg-x11-server in versions before 21.1.2 and before 1.20.14. An out-of-bounds access can occur in the SProcXFixesCreatePointerBarrier function. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

A flaw was found in xorg-x11-server in versions before 21.1.2 and before 1.20.14. An out-of-bounds access can occur in the SwapCreateRegister function. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

A flaw was found in xorg-x11-server in versions before 21.1.2 and before 1.20.14. An out-of-bounds access can occur in the SProcScreenSaverSuspend function. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

A flaw was found in X.Org Server before xorg-x11-server 1.20.9. An Integer underflow leading to heap-buffer overflow may lead to a privilege escalation vulnerability. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

A flaw was found in X.Org Server before xorg-x11-server 1.20.9. An Integer underflow leading to heap-buffer overflow may lead to a privilege escalation vulnerability. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

A flaw was found in the way xserver memory was not properly initialized. This could leak parts of server memory to the X client. In cases where Xorg server runs with elevated privileges, this could result in possible ASLR bypass. Xorg-server before version 1.20.9 is vulnerable.

A flaw was found in xorg-x11-server before 1.20.9. An integer underflow in the X input extension protocol decoding in the X server may lead to arbitrary access of memory contents. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

It was found that xorg-x11-server before 1.19.0 including uses memcmp() to check the received MIT cookie against a series of valid cookies. If the cookie is correct, it is allowed to attach to the Xorg session. Since most memcmp() implementations return after an invalid byte is seen, this causes a time difference between a valid and invalid byte, which could allow an efficient brute force attack.

Missing length validation was found in XFIXES extension

Upstream patch:

https://cgit.freedesktop.org/xorg/xserver/commit/?id=55caa8b08c84af2b50fbc936cf334a5a93dd7db5

Missing length validation was found in XINERAMA extension.

Upstream patch:

https://cgit.freedesktop.org/xorg/xserver/commit/?id=cad5a1050b7184d828aef9c1dd151c3ab649d37e

Missing length validation was found in XFree86 DGA extension.

Upstream patch:

https://cgit.freedesktop.org/xorg/xserver/commit/?id=1b1d4c04695dced2463404174b50b3581dbd857b