Arista Networks EOS Linux Kernel TCP Multiple DoS (SA0041)

high Nessus Plugin ID 134303
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Synopsis

The version of Arista Networks EOS running on the remote device is affected by multiple denial of service (DoS) vulnerabilities.

Description

The 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.

Solution

Upgrade to Arista Networks EOS version 4.22.1F, 4.21.7M, 4.20.14M, 4.19.13M, 4.18.12M or later or 4.21.2.3F or 4.21.6.1.1F, or apply the patch from the vendor advisory.

See Also

http://www.nessus.org/u?0073e92b

Plugin Details

Severity: High

ID: 134303

File Name: arista_eos_sa0041.nasl

Version: 1.4

Type: combined

Family: Misc.

Published: 3/6/2020

Updated: 3/10/2020

Dependencies: arista_eos_detect.nbin

Configuration: Enable paranoid mode

Risk Information

CVSS Score Source: CVE-2019-11477

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

Risk Factor: High

Base Score: 7.8

Temporal Score: 5.8

Vector: AV:N/AC:L/Au:N/C:N/I:N/A:C

Temporal Vector: E:U/RL:OF/RC:C

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Temporal Vector: E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:arista:eos

Required KB Items: Host/Arista-EOS/Version, Settings/ParanoidReport

Exploit Ease: No known exploits are available

Patch Publication Date: 6/26/2019

Vulnerability Publication Date: 6/18/2019

Reference Information

CVE: CVE-2019-11477, CVE-2019-11478, CVE-2019-11479

BID: 108798, 108801, 108818