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.

References

• https://nvd.nist.gov/vuln/detail/CVE-2015-8370
• https://security.gentoo.org/glsa/201512-03
• 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
• http://www.openwall.com/lists/oss-security/2024/01/15/3