Bug 1343072 (CVE-2015-8899) - CVE-2015-8899 dnsmasq: Denial-of-service when empty address from DNS overlays A record from hosts
Summary: CVE-2015-8899 dnsmasq: Denial-of-service when empty address from DNS overlays...
Keywords:
Status: CLOSED NOTABUG
Alias: CVE-2015-8899
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
low
low
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 1343073
Blocks: 1343074
TreeView+ depends on / blocked
 
Reported: 2016-06-06 12:52 UTC by Andrej Nemec
Modified: 2021-02-17 03:46 UTC (History)
21 users (show)

Fixed In Version:
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Doc Text:
A NULL pointer dereference flaw was found in dmsmasq in the cache_insert() function. An attacker could exploit this flaw by locally defining an A or AAAA record in the /etc/hosts file that is not in the upstream server. When the upstream server sends a reply that the same name is empty, dmsmasq crashes (denial of service).
Clone Of:
Environment:
Last Closed: 2016-06-11 02:28:11 UTC
Embargoed:

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Description Andrej Nemec 2016-06-06 12:52:48 UTC 
A vulnerability was found in dmsmasq. A Denial-of-service will occur when an A or AAAA record is defined locally, in a hosts file, and an upstream server sends a reply that the same name is empty.

Upstream bug:

http://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2016q2/010479.html

Upstream fix:

http://thekelleys.org.uk/gitweb/?p=dnsmasq.git;a=commit;h=41a8d9e99be9f2cc8b02051dd322cb45e0faac87
Comment 1 Andrej Nemec 2016-06-06 12:53:45 UTC 
Created dnsmasq tracking bugs for this issue:

Affects: fedora-all [bug 1343073]
Comment 2 Doran Moppert 2016-06-07 01:40:21 UTC 
Low impact as the worst this can cause is a denial of service.

Vulnerable code was introduced in v2.73:  all RHEL versions ship earlier
versions of dnsmasq which are not affected by this issue.
Comment 3 Summer Long 2016-06-09 23:43:19 UTC 
Created attachment 1166437 [details]
Patch for version2.75

http://thekelleys.org.uk/gitweb/?p=dnsmasq.git;a=patch;h=41a8d9e99be9f2cc8b02051dd322cb45e0faac87
Comment 4 Summer Long 2016-06-10 00:17:54 UTC 
Same as RHEL (see comment #2). All RHOSP versions ship earlier dnsmasq versions (either 2.48 or 2.66), and are not affected by this issue.
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