Bug 1182623 (CVE-2021-27862)

Summary: VUL-0: CVE-2021-27862: kernel-source: Bypass using 802.3 headers
Product: [Novell Products] SUSE Security Incidents Reporter: Alexandros Toptsoglou <atoptsoglou>
Component: IncidentsAssignee: Security Team bot <security-team>
Status: RESOLVED INVALID QA Contact: Security Team bot <security-team>
Severity: Normal    
Priority: P3 - Medium CC: bpetkov, denis.kirjanov, jack, meissner, mhocko, mkubecek, rfrohl, stoyan.manolov, tiwai
Version: unspecified   
Target Milestone: ---   
Hardware: Other   
OS: Other   
URL: https://smash.suse.de/issue/343695/
Whiteboard:
Found By: --- Services Priority:
Business Priority: Blocker: ---
Marketing QA Status: --- IT Deployment: ---

Comment 13 Robert Frohl 2022-09-28 12:09:31 UTC
*** Bug 1203837 has been marked as a duplicate of this bug. ***
Comment 14 Robert Frohl 2022-09-28 12:10:00 UTC
CVE-2021-27862

Layer 2 network filtering capabilities such as IPv6 RA guard can be bypassed
using LLC/SNAP headers with invalid length and Ethernet to Wifi frame conversion
(and optionally VLAN0 headers).

References:
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-27862
https://www.cve.org/CVERecord?id=CVE-2021-27862
https://standards.ieee.org/ieee/802.2/1048/
https://datatracker.ietf.org/doc/draft-ietf-v6ops-ra-guard/08/
Comment 16 Takashi Iwai 2022-12-01 13:54:08 UTC
Denis, any progress on this bug?

Through a quick glance, it's not clear whether any relevant upstream fix is present -- or whether we would need any fix, above all, though...
Comment 17 Jan Kara 2023-01-09 14:56:52 UTC
As I'm reading comment 2, Linux is affected by this problem when it acts as a router between ethernet and WiFi. Not a common usecase of our product but perhaps possible. No sure if there are any fixes for this though... Denis can you have a look and tell us whether there's something to fix for us?
Comment 19 Robert Frohl 2023-03-09 10:02:43 UTC
configuration issue with the kernel that we will not fix, users should handle the problem by applying proper configuration to their systems.