Bug 9473

Summary: bind: CVE-2016-2088 (jethro)
Product: [Build System, Metadata & Runtime] OE-Core Reporter: Jussi Kukkonen <jku>
Component: connectivityAssignee: Jussi Kukkonen <jku>
Status: RESOLVED FIXED QA Contact:
Severity: major    
Priority: Medium CC: akuster, meta.mr.watcher, meta.watcher, randy.macleod, sona.sarmadi
Version: 2.0   
Target Milestone: 2.0.3   
Hardware: All   
OS: Multiple   
Whiteboard:
OS type for building Yocto: --- Type of Regression: ---
Verified: Documentation change: No (bug/feature does not impact docs)
Bug Depends on: 9438    
Bug Blocks:    

Description Jussi Kukkonen 2016-04-18 12:30:37 UTC 
+++ This bug was initially created as a clone of Bug #9438 +++


Versions affected: 
9.10.0 -> 9.10.3-P3
Severity:  High
Exploitable:  Remotely

Description:

BIND 9.10 has preliminary support for DNS cookies (or source identity tokens), a proposed mechanism designed to allow lightweight transaction security between a querying party and a nameserver. An error in the BIND code implementing support for this optional feature permits a deliberately misconstructed packet containing multiple cookie options to cause named to terminate with an INSIST assertion failure in resolver.c if DNS cookie support is enabled in the server.  Only servers with DNS cookie support enabled at build time can be affected by this defect; in servers which do not have DNS cookie support selected any cookies encountered will be ignored as unknown option types.

Impact:

Servers which are built with DNS cookie support enabled are vulnerable to denial of service if an attacker can cause them to receive and process a response that contains multiple cookie options.

References:
https://kb.isc.org/article/AA-01351
Comment 1 Jussi Kukkonen 2016-04-18 12:37:49 UTC 
It's worth noting that bind as built with the oe-core recipe is not really at risk: Only servers which are built with DNS cookie support (--enable-sit) are vulnerable to denial of service.
Comment 2 Armin Kuster 2016-07-23 14:00:56 UTC 
jethro patch sent.