Vulnerability CVE-2015-8370

Vulnerability CVE-2015-8370

Published: 2015-12-16 Modified: 2015-12-17

Description:

Multiple integer underflows in Grub2 1.98 through 2.02 allow physically proximate attackers to bypass authentication, obtain sensitive information, or cause a denial of service (disk corruption) via backspace characters in the (1) grub_username_get function in grub-core/normal/auth.c or the (2) grub_password_get function in lib/crypto.c, which trigger an "Off-by-two" or "Out of bounds overwrite" memory error.

See advisories in our WLB2 database:

	Topic	Author	Date
High	Grub2 Authentication Bypass 0-Day	hmarco	15.12.2015

Type:

CWE-264

(Permissions, Privileges, and Access Controls)

CVSS2 => (AV:L/AC:M/Au:N/C:C/I:C/A:C)

CVSS Base Score	Impact Subscore	Exploitability Subscore
6.9/10	10/10	3.4/10

Exploit range	Attack complexity	Authentication
Local	Medium	No required
Confidentiality impact	Integrity impact	Availability impact
Complete	Complete	Complete

Affected software
GNU -> Grub2
Fedoraproject -> Fedora

References:

http://hmarco.org/bugs/CVE-2015-8370-Grub2-authentication-bypass.html

http://lists.fedoraproject.org/pipermail/package-announce/2015-December/173703.html

http://lists.fedoraproject.org/pipermail/package-announce/2015-December/174049.html

http://lists.opensuse.org/opensuse-security-announce/2015-12/msg00037.html

http://lists.opensuse.org/opensuse-security-announce/2015-12/msg00039.html

http://lists.opensuse.org/opensuse-security-announce/2015-12/msg00040.html

http://lists.opensuse.org/opensuse-security-announce/2015-12/msg00041.html

http://lists.opensuse.org/opensuse-security-announce/2015-12/msg00043.html

http://lists.opensuse.org/opensuse-security-announce/2015-12/msg00044.html

http://lists.opensuse.org/opensuse-security-announce/2016-01/msg00003.html

http://packetstormsecurity.com/files/134831/Grub2-Authentication-Bypass.html

http://rhn.redhat.com/errata/RHSA-2015-2623.html

http://seclists.org/fulldisclosure/2015/Dec/69

http://www.debian.org/security/2015/dsa-3421

http://www.openwall.com/lists/oss-security/2015/12/15/6

http://www.oracle.com/technetwork/topics/security/cpujan2016-2367955.html

http://www.oracle.com/technetwork/topics/security/linuxbulletinoct2015-2719645.html

http://www.securityfocus.com/archive/1/537115/100/0/threaded

http://www.securityfocus.com/bid/79358

http://www.securitytracker.com/id/1034422

http://www.ubuntu.com/usn/USN-2836-1

https://security.gentoo.org/glsa/201512-03

Vulnerability CVE-2015-8370

See advisories in our WLB2 database:

High

Grub2 Authentication Bypass 0-Day

CWE-264

CVSS2 => (AV:L/AC:M/Au:N/C:C/I:C/A:C)

6.9/10

10/10

3.4/10

Local

Medium

No required

Complete

Complete

Complete

Affected software

References: