In the Linux kernel, the following vulnerability has been resolved:
ipv4: validate checksum_start before completing checksum
If a packet with bad checksum metadata gets into the ipv4 stack, skb_checksum_help can corrupt the network header and cause a bunch of mischief.
This was discovered and reported by Paulos, and has been reporoduced by others independently since.
We really shouldn't allow such packets in, but as a defence in depth measure, let's also check before we complete the checksum.
A more complete validation at input is forthcoming, but needs more work.
Exploitability
AV:LAC:LPR:NUI:NScope
S:CImpact
C:HI:HA:H9.3/CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H