USN-1571-1: DHCP vulnerability | Ubuntu security notices

Packages

dhcp3 - DHCP server and client
isc-dhcp - DHCP server and client

Details

Glen Eustace discovered that the DHCP server incorrectly handled IPv6
expiration times. A remote attacker could use this issue to cause DHCP to
crash, resulting in a denial of service. This issue only affected Ubuntu
11.04, Ubuntu 11.10 and Ubuntu 12.04 LTS. (CVE-2012-3955)

Dan Rosenberg discovered that the DHCP AppArmor profile could be escaped by
using environment variables. This update mitigates the issue by sanitizing
certain variables in the DHCP shell scripts.

Glen Eustace discovered that the DHCP server incorrectly handled IPv6
expiration times. A remote attacker could use this issue to cause DHCP to
crash, resulting in a denial of service. This issue only affected Ubuntu
11.04, Ubuntu 11.10 and Ubuntu 12.04 LTS. (CVE-2012-3955)

Dan Rosenberg discovered that the DHCP AppArmor profile could be escaped by
using environment variables. This update mitigates the issue by sanitizing
certain variables in the DHCP shell scripts.

Update instructions

In general, a standard system update will make all the necessary changes.

Learn more about how to get the fixes.

Ubuntu Release	Package Version
12.04 precise	isc-dhcp-server – 4.1.ESV-R4-0ubuntu5.5
12.04 precise	isc-dhcp-client – 4.1.ESV-R4-0ubuntu5.5
11.10 oneiric	isc-dhcp-server – 4.1.1-P1-17ubuntu10.5
11.10 oneiric	isc-dhcp-client – 4.1.1-P1-17ubuntu10.5
11.04 natty	isc-dhcp-server – 4.1.1-P1-15ubuntu9.6
11.04 natty	isc-dhcp-client – 4.1.1-P1-15ubuntu9.6
10.04 lucid	dhcp3-client – 3.1.3-2ubuntu3.4
10.04 lucid	dhcp3-server – 3.1.3-2ubuntu3.4

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References

CVE-2012-3955