Bug 1683326 (CVE-2018-12178)

Summary:	CVE-2018-12178 edk2: improper DNS packet size check
Product:	[Other] Security Response	Reporter:	Laura Pardo <lpardo>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED NOTABUG	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	unspecified	CC:	berrange, bmcclain, dblechte, dfediuck, eedri, kraxel, lersek, mgoldboi, michal.skrivanek, pbonzini, philmd, sbonazzo, sherold, virt-maint, virt-maint, yturgema
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:	A missing check leads to an out-of-bounds read and write flaw in NetworkPkg/DnsDxe as shipped in edk2, when it parses DNS responses. A remote attacker who controls the DNS server used by the vulnerable firmware may use this flaw to make the system crash.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2019-06-10 10:48:54 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:	1683330, 1683331
Bug Blocks:	1683333

Description Laura Pardo 2019-02-26 15:43:58 UTC

A flaw was found in edk2. The DNS driver only checks the received packet size against the minimum DNS header size in DnsOnPacketReceived(), later it accesses the QueryName and QuerySection beyond the header scope, which might cause the pointer within DNS driver points to an invalid entry or modifies the memory content beyond the header scope.


Upstream Bug:
https://bugzilla.tianocore.org/show_bug.cgi?id=809

Upstream Patch:
https://lists.01.org/pipermail/edk2-devel/2019-February/037251.html

Comment 1 Laura Pardo 2019-02-26 15:48:59 UTC

Created edk2 tracking bugs for this issue:

Affects: epel-all [bug 1683331]
Affects: fedora-all [bug 1683330]

Comment 4 Riccardo Schirone 2019-02-27 14:10:22 UTC

Statement:

This issue did not affect the versions of OVMF as shipped with Red Hat Enterprise Linux 7 as they were not compiled with HTTP_BOOT_ENABLE set, thus they do not contain the vulnerable code.