In the Linux kernel, the following vulnerability has been resolved:
inet: RAW sockets using IPPROTO_RAW MUST drop incoming ICMP
Yizhou Zhao reported that simply having one RAW socket on protocol IPPROTO_RAW (255) was dangerous.
socket(AF_INET, SOCK_RAW, 255);
A malicious incoming ICMP packet can set the protocol field to 255 and match this socket, leading to FNHE cache changes.
inner = IP(src="192.168.2.1", dst="8.8.8.8", proto=255)/Raw("TEST") pkt = IP(src="192.168.1.1", dst="192.168.2.1")/ICMP(type=3, code=4, nexthopmtu=576)/inner
"man 7 raw" states:
A protocol of IPPROTO_RAW implies enabled IP_HDRINCL and is able to send any IP protocol that is specified in the passed header. Receiving of all IP protocols via IPPROTO_RAW is not possible using raw sockets.
Make sure we drop these malicious packets.
Exploitability
AV:NAC:LPR:NUI:NScope
S:UImpact
C:NI:HA:H9.1/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H