CVE-2023-53333: 
Linux Kernel vulnerability analysis and mitigation

CVE-2023-53333 is a vulnerability discovered in the Linux kernel's netfilter conntrack DCCP packet handling. The vulnerability was recently published to the CVE List and included in the NVD dataset (NVD).

The vulnerability exists in the nfconntrackdccppacket() function where only the basic header is copied to a stack buffer using skbheaderpointer(), but no additional data is pulled from the packet depending on the content (dh->dccphdoff and/or dh->dccphx). This results in dccpackseq() reading beyond the dh buffer, causing a stack-out-of-bounds condition. The issue was identified through KASAN detection showing stack-out-of-bounds access in nfconntrackdccp_packet+0x1134/0x11c0 (NVD).

The vulnerability allows reading past the end of an allocated buffer, which could potentially lead to information disclosure or system crashes. The issue affects the Linux kernel's netfilter subsystem, specifically the DCCP connection tracking functionality (NVD).

The fix involves increasing the stack buffer size to include room for extra sequence numbers and all known DCCP packet type headers, then performing additional validation of the basic header. Additionally, packets lacking required 48-bit sequence bits are now marked as invalid. The maintainer has also indicated plans to remove DCCP conntrack support later in the year (NVD).