CVE-2023-53033: 
Linux Kernel vulnerability analysis and mitigation

CVE-2023-53033 is a vulnerability discovered in the Linux kernel's netfilter component, specifically in the nft_payload functionality. The issue involves incorrect arithmetic operations when fetching VLAN header bits. The vulnerability was disclosed on March 27, 2025 (NVD).

The vulnerability occurs when the offset + length calculation goes beyond the ethernet + vlan header boundaries. In such cases, the length is adjusted to copy bytes within the vlan_ethhdr scratchpad area, but the remaining bytes beyond ethernet + vlan header are copied directly from the skbuff data area. The issue specifically involves an incorrect arithmetic operator where subtraction should be used instead of addition when handling the size of the vlan header in double-tagged packets (NVD).

The vulnerability affects the Linux kernel's network filtering capabilities, particularly in handling VLAN headers. While specific impact details are not fully disclosed, the issue could potentially lead to memory safety problems when processing network packets with specific VLAN configurations (NVD).

The vulnerability has been resolved through a fix that corrects the arithmetic operator used in the VLAN header size calculation. The fix specifically addresses the handling of double-tagged packets by changing the addition operation to subtraction when adjusting the length (NVD).