FreeBSD Security Advisory FreeBSD-SA-09:10.ipv6

Type securityvulns
Reporter Securityvulns
Modified 2009-06-14T00:00:00



============================================================================= FreeBSD-SA-09:10.ipv6 Security Advisory The FreeBSD Project

Topic: Missing permission check on SIOCSIFINFO_IN6 ioctl

Category: core Module: netinet6 Announced: 2009-06-10 Credits: Hiroki Sato Affects: All supported versions of FreeBSD. Corrected: 2009-06-10 10:31:11 UTC (RELENG_7, 7.2-STABLE) 2009-06-10 10:31:11 UTC (RELENG_7_2, 7.2-RELEASE-p1) 2009-06-10 10:31:11 UTC (RELENG_7_1, 7.1-RELEASE-p6) 2009-06-10 10:31:11 UTC (RELENG_6, 6.4-STABLE) 2009-06-10 10:31:11 UTC (RELENG_6_4, 6.4-RELEASE-p5) 2009-06-10 10:31:11 UTC (RELENG_6_3, 6.3-RELEASE-p11)

For general information regarding FreeBSD Security Advisories, including descriptions of the fields above, security branches, and the following sections, please visit <URL:>.

I. Background

IPv6 is a new Internet Protocol, designed to replace (and avoid many of the problems with) the current Internet Protocol (version 4). Many properties of the FreeBSD IPv6 network stack can be configured via the ioctl(2) interface.

II. Problem Description

The SIOCSIFINFO_IN6 ioctl is missing a necessary permissions check.

III. Impact

Local users, including non-root users and users inside jails, can set some IPv6 interface properties. These include changing the link MTU and disabling interfaces entirely. Note that this affects IPv6 only; IPv4 functionality cannot be affected by exploiting this vulnerability.

IV. Workaround

No workaround is available, but systems without local untrusted users are not vulnerable.

V. Solution

Perform one of the following:

1) Upgrade your vulnerable system to 6-STABLE, or 7-STABLE, or to the RELENG_7_2, RELENG_7_1, RELENG_6_4, or RELENG_6_3 security branch dated after the correction date.

2) To patch your present system:

The following patches have been verified to apply to FreeBSD 6.3, 6.4, 7.1, and 7.2 systems.

a) Download the relevant patch from the location below, and verify the detached PGP signature using your PGP utility.

[FreeBSD 6.x]



[FreeBSD 7.x]



b) Apply the patch.

cd /usr/src

patch < /path/to/patch

c) Recompile your kernel as described in <URL:> and reboot the system.

VI. Correction details

The following list contains the revision numbers of each file that was corrected in FreeBSD.


Branch Revision Path

RELENG_6 src/sys/netinet6/in6.c RELENG_6_4 src/UPDATING 1.416. src/sys/conf/ src/sys/netinet6/in6.c RELENG_6_3 src/UPDATING 1.416. src/sys/conf/ src/sys/netinet6/in6.c RELENG_7 src/sys/netinet6/in6.c RELENG_7_2 src/UPDATING 1.507. src/sys/conf/ src/sys/netinet6/in6.c RELENG_7_1 src/UPDATING 1.507. src/sys/conf/ src/sys/netinet6/in6.c


Branch/path Revision

stable/6/ r193893 releng/6.4/ r193893 releng/6.3/ r193893 stable/7/ r193893 releng/7.2/ r193893 releng/7.1/ r193893

VII. References

The latest revision of this advisory is available at -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (FreeBSD)

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