CVE-2015-0239

The em_sysenter function in arch/x86/kvm/emulate.c in the Linux kernel before 3.18.5, when the guest OS lacks SYSENTER MSR initialization, allows guest OS users to gain guest OS privileges or cause a denial of service (guest OS crash) by triggering use of a 16-bit code segment for emulation of a SYSENTER instruction.

Weakness

The product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor.

Affected Software

Potential Mitigations

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/122.html
• https://cwe.mitre.org/data/definitions/233.html
• https://cwe.mitre.org/data/definitions/58.html

References

• http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=f3747379accba8e95d70cec0eae0582c8c182050
• http://permalink.gmane.org/gmane.linux.kernel.commits.head/502245
• http://rhn.redhat.com/errata/RHSA-2015-1272.html
• http://www.debian.org/security/2015/dsa-3170
• http://www.kernel.org/pub/linux/kernel/v3.x/ChangeLog-3.18.5
• http://www.mandriva.com/security/advisories?name=MDVSA-2015:058
• http://www.openwall.com/lists/oss-security/2015/01/27/6
• http://www.oracle.com/technetwork/topics/security/linuxbulletinjan2016-2867209.html
• http://www.oracle.com/technetwork/topics/security/linuxbulletinoct2015-2719645.html
• http://www.securityfocus.com/bid/72842
• http://www.ubuntu.com/usn/USN-2513-1
• http://www.ubuntu.com/usn/USN-2514-1
• http://www.ubuntu.com/usn/USN-2515-1
• http://www.ubuntu.com/usn/USN-2516-1
• http://www.ubuntu.com/usn/USN-2517-1
• http://www.ubuntu.com/usn/USN-2518-1
• https://bugzilla.redhat.com/show_bug.cgi?id=1186448
• https://github.com/torvalds/linux/commit/f3747379accba8e95d70cec0eae0582c8c182050