X-server: processing of requests from customers with different bytes order was disabled

to the code base of the X.org server and the DDX component of the Xwayland accepted change , default connecting customers with systems that have otherwise Byta order . The reason is the presence of potential problems with safety in the bypass transformation code, Which is not tested enough and may turn out to be a weak place when organizing attacks on the system. At the same time, in practice, the transformation of byte order has recently been used extremely rarely, since the working stations on which the X-server is launched, as a rule, are equipped with processors from the Little-Endian bytes (from the younger to the older byte), and the connection of the X-clients to them With the Big-Endian order, such as the S390X platform (IBM ZSYSTEMS), is a rarity.

Thus, it was decided that it is more advisable to disconnect by default the processing of customers unnecessary in 99% of cases with other bytes, but to increase the overall security of the X-server. For users who need such a transformation, the ALLOWBYTESWAPEDCLIENTS configuration parameter and command line option+ByteswappedClents have been added, which allow you to return old behavior. The change will be included in the following significant issues of X.org Server and XWayland, but since there are no plans for their formation yet, it is recommended to transfer the change to current packages from X.org Server and XWALAND (for example, a change will be used in Fedora Linux 38).

/Media reports cited above.