Bug 1637570 (CVE-2018-18065)

Summary: CVE-2018-18065 net-snmp: NULL pointer exception in _set_key in agent/helpers/table_container.c resulting in a denial of service
Product: [Other] Security Response Reporter: Andrej Nemec <anemec>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED NOTABUG QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: bmcclain, dblechte, dfediuck, eedri, jridky, jsafrane, mgoldboi, michal.skrivanek, sbonazzo, sherold, ylavi, yozone
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: net-snmp 5.8 Doc Type: If docs needed, set a value
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2018-10-12 17:05:25 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On: 1637573    
Bug Blocks: 1637575    

Description Andrej Nemec 2018-10-09 13:50:54 UTC 
It was found that _set_key in agent/helpers/table_container.c in Net-SNMP before 5.8 has a NULL Pointer Exception bug that can be used by an authenticated attacker to remotely cause the instance to crash via a crafted UDP packet, resulting in Denial of Service.

References:

https://dumpco.re/blog/net-snmp-5.7.3-remote-dos

Upstream patch:

https://sourceforge.net/p/net-snmp/code/ci/7ffb8e25a0db851953155de91f0170e9bf8c457d/
Comment 1 Andrej Nemec 2018-10-09 13:59:13 UTC 
Created net-snmp tracking bugs for this issue:

Affects: fedora-all [bug 1637573]
Comment 2 Scott Gayou 2018-10-11 19:59:46 UTC 
Unable to reproduce on any version of RHEL using instructions. This appears to be a duplicate of CVE-2015-5621. See the reference page for those details. "Update: "vuln1" was assigned CVE-2015-5621 (see references), therefore CVE-2018-18066 has been marked as duplicate."

This looks to have been patched in RHEL6 and RHEL7 at least via https://bugzilla.redhat.com/show_bug.cgi?id=1212408. I expected that it would trigger on RHEL5 at least, but it does not.
Comment 3 Scott Gayou 2018-10-11 20:09:34 UTC 
More notes about duplicate CVE:

https://seclists.org/oss-sec/2018/q4/38