In PHP versions 7.4.x below 7.4.28, 8.0.x below 8.0.16, and 8.1.x below 8.1.3, when using filter functions with FILTER_VALIDATE_FLOAT filter and min/max limits, if the filter fails, there is a possibility to trigger use of allocated memory after free, which can result it crashes, and potentially in overwrite of other memory chunks and RCE. This issue affects: code that uses FILTER_VALIDATE_FLOAT with min/max limits.
main/streams/xp_socket.c in PHP 7.x before 2017-03-07 misparses fsockopen calls, such as by interpreting fsockopen('127.0.0.1:80', 443) as if the address/port were 127.0.0.1:80:443, which is later truncated to 127.0.0.1:80. This behavior has a security risk if the explicitly provided port number (i.e., 443 in this example) is hardcoded into an application as a security policy, but the hostname argument (i.e., 127.0.0.1:80 in this example) is obtained from untrusted input.