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 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.

A flaw was found in X.Org Server before xorg-x11-server 1.20.9. An Out-Of-Bounds access in XkbSetNames function may lead to a privilege escalation vulnerability. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

An integer overflow vulnerability leading to a double-free was found in libX11. This flaw allows a local privileged attacker to cause an application compiled with libX11 to crash, or in some cases, result in arbitrary code execution. The highest threat from this flaw is to confidentiality, 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.

An integer overflow leading to a heap-buffer overflow was found in The X Input Method (XIM) client was implemented in libX11 before version 1.6.10. As per upstream this is security relevant when setuid programs call XIM client functions while running with elevated privileges. No such programs are shipped with Red Hat Enterprise Linux.

"" In X.Org X Server 1.20.4, there is a stack-based buffer overflow in the function XQueryKeymap. For example, by sending ct.c_char 1000 times, an attacker can cause a denial of service (application crash) or possibly have unspecified other impact. Note: It is disputed if the X.Org X Server is involved or if there is a stack overflow.

A flaw was found in xorg-x11-server before 1.20.3. An incorrect permission check for -modulepath and -logfile options when starting Xorg. X server allows unprivileged users with the ability to log in to the system via physical console to escalate their privileges and run arbitrary code under root privileges.

An issue was discovered in libX11 through 1.6.5. The function XListExtensions in ListExt.c is vulnerable to an off-by-one error caused by malicious server responses, leading to DoS or possibly unspecified other impact.

An issue was discovered in XListExtensions in ListExt.c in libX11 through 1.6.5. A malicious server can send a reply in which the first string overflows, causing a variable to be set to NULL that will be freed later on, leading to DoS (segmentation fault).