Bug 952189 (CVE-2015-2696) - VUL-0: CVE-2015-2696: krb5: IAKERB context aliasing bugs
Summary: VUL-0: CVE-2015-2696: krb5: IAKERB context aliasing bugs
Status: RESOLVED FIXED
Alias: CVE-2015-2696
Product: SUSE Security Incidents
Classification: Novell Products
Component: Incidents (show other bugs)
Version: unspecified
Hardware: Other Other
: P3 - Medium : Major
Target Milestone: ---
Assignee: Howard Guo
QA Contact: Security Team bot
URL: https://smash.suse.de/issue/158283/
Whiteboard: CVSSv2:NVD:CVE-2015-2696:7.1:(AV:N/AC...
Keywords:
Depends on:
Blocks:
 
Reported: 2015-10-27 12:08 UTC by Andreas Stieger
Modified: 2016-04-27 19:06 UTC (History)
3 users (show)

See Also:
Found By: Security Response Team
Services Priority:
Business Priority:
Blocker: ---
Marketing QA Status: ---
IT Deployment: ---


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Description Andreas Stieger 2015-10-27 12:08:22 UTC
https://github.com/krb5/krb5/commit/e04f0283516e80d2f93366e0d479d13c9b5c8c2a

Fix IAKERB context aliasing bugs [CVE-2015-2696]

The IAKERB mechanism currently replaces its context handle with the
krb5 mechanism handle upon establishment, under the assumption that
most GSS functions are only called after context establishment.  This
assumption is incorrect, and can lead to aliasing violations for some
programs.  Maintain the IAKERB context structure after context
establishment and add new IAKERB entry points to refer to it with that
type.  Add initiate and established flags to the IAKERB context
structure for use in gss_inquire_context() prior to context
establishment.

CVE-2015-2696:

In MIT krb5 1.9 and later, applications which call
gss_inquire_context() on a partially-established IAKERB context can
cause the GSS-API library to read from a pointer using the wrong type,
generally causing a process crash.  Java server applications using the
native JGSS provider are vulnerable to this bug.  A carefully crafted
IAKERB packet might allow the gss_inquire_context() call to succeed
with attacker-determined results, but applications should not make
access control decisions based on gss_inquire_context() results prior
to context establishment.

    CVSSv2 Vector: AV:N/AC:M/Au:N/C:N/I:N/A:C/E:POC/RL:OF/RC:C

[ghudson@mit.edu: several bugfixes, style changes, and edge-case
behavior changes; commit message and CVE description]

SLE 12 and up.
openSUSE 13.1, 13.2, Leap 42.1 and Tumbleweed.

https://github.com/krb5/krb5/commit/e04f0283516e80d2f93366e0d479d13c9b5c8c2a
More tests:
https://github.com/krb5/krb5/commit/a705b1160ce7f0c5f23b9859c4c6c707503fbfdc

References:
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2015-2696
http://people.canonical.com/~ubuntu-security/cve/2015/CVE-2015-2696.html
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-2696
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=803084
Comment 1 Swamp Workflow Management 2015-10-27 23:00:25 UTC
bugbot adjusting priority
Comment 2 Bernhard Wiedemann 2015-10-29 16:00:50 UTC
This is an autogenerated message for OBS integration:
This bug (952189) was mentioned in
https://build.opensuse.org/request/show/341522 13.1 / krb5
https://build.opensuse.org/request/show/341525 13.2 / krb5
Comment 3 Swamp Workflow Management 2015-11-04 09:12:09 UTC
SUSE-SU-2015:1897-1: An update that solves three vulnerabilities and has one errata is now available.

Category: security (important)
Bug References: 948011,952188,952189,952190
CVE References: CVE-2015-2695,CVE-2015-2696,CVE-2015-2697
Sources used:
SUSE Linux Enterprise Software Development Kit 12 (src):    krb5-1.12.1-19.1
SUSE Linux Enterprise Server 12 (src):    krb5-1.12.1-19.1
SUSE Linux Enterprise Desktop 12 (src):    krb5-1.12.1-19.1
Comment 4 Swamp Workflow Management 2015-11-06 17:12:44 UTC
openSUSE-SU-2015:1928-1: An update that fixes three vulnerabilities is now available.

Category: security (important)
Bug References: 952188,952189,952190
CVE References: CVE-2015-2695,CVE-2015-2696,CVE-2015-2697
Sources used:
openSUSE 13.2 (src):    krb5-1.12.2-15.1, krb5-mini-1.12.2-15.1
openSUSE 13.1 (src):    krb5-1.11.3-3.21.1, krb5-mini-1.11.3-3.21.1
Comment 5 Swamp Workflow Management 2015-11-16 10:13:01 UTC
openSUSE-SU-2015:1997-1: An update that solves three vulnerabilities and has one errata is now available.

Category: security (important)
Bug References: 948011,952188,952189,952190
CVE References: CVE-2015-2695,CVE-2015-2696,CVE-2015-2697
Sources used:
openSUSE Leap 42.1 (src):    krb5-1.12.1-21.1, krb5-mini-1.12.1-21.1
Comment 6 Howard Guo 2015-11-20 09:07:44 UTC
The update has been released, thus closing the bug report.