SynopsisThe version of Arista Networks EOS running on the remote device is affected by multiple denial of service (DoS) vulnerabilities.
DescriptionThe version of Arista Networks EOS running on the remote device is affected by the following denial of service (DoS) vulnerabilities related to TCP networking in the Linux kernel, which can be exploited by a remote, unauthenticated attacker:
- SACK Panic. The TCP_SKB_CB(skb)->tcp_gso_segs value is subject to an integer overflow in the Linux kernel when handling TCP Selective Acknowledgments (SACKs). (CVE-2019-11477)
- SACK Slowness. The TCP retransmission queue implementation in tcp_fragment in the Linux kernel can be fragmented when handling certain TCP Selective Acknowledgment (SACK) sequences. (CVE-2019-11478)
- The Linux kernel default MSS is hard-coded to 48 bytes. This allows a remote peer to fragment TCP resend queues significantly more than if a larger MSS were enforced. (CVE-2019-11479)
Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.
SolutionUpgrade to Arista Networks EOS version 4.22.1F, 4.21.7M, 4.20.14M, 4.19.13M, 4.18.12M or later or 126.96.36.199F or 188.8.131.52.1F, or apply the patch from the vendor advisory.