CVE-2021-32761: Integer overflow issues with *BIT commands on 32-bit systems

Redis is an in-memory database that persists on disk. A vulnerability involving out-of-bounds read and integer overflow to buffer overflow exists starting with version 2.2 and prior to versions 5.0.13, 6.0.15, and 6.2.5. On 32-bit systems, Redis BIT command are vulnerable to integer overflow that can potentially be exploited to corrupt the heap, leak arbitrary heap contents or trigger remote code execution. The vulnerability involves changing the default proto-max-bulk-len configuration parameter to a very large value and constructing specially crafted commands bit commands. This problem only affects Redis on 32-bit platforms, or compiled as a 32-bit binary. Redis versions 5.0.3m 6.0.15, and 6.2.5 contain patches for this issue. An additional workaround to mitigate the problem without patching the redis-server executable is to prevent users from modifying the proto-max-bulk-len configuration parameter. This can be done using ACL to restrict unprivileged users from using the CONFIG SET command.