CVE-2015-5600

Vulnerability Description

The kbdint_next_device function in auth2-chall.c in sshd in OpenSSH through 6.9 does not properly restrict the processing of keyboard-interactive devices within a single connection, which makes it easier for remote attackers to conduct brute-force attacks or cause a denial of service (CPU consumption) via a long and duplicative list in the ssh -oKbdInteractiveDevices option, as demonstrated by a modified client that provides a different password for each pam element on this list.

CVSS Score

Affected Products

Related Weaknesses (CWE)

References

• http://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/auth2-chall.c
• http://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/auth2-chall.c.diff?r1=1
• http://kb.juniper.net/InfoCenter/index?page=content&id=JSA10697
• http://lists.apple.com/archives/security-announce/2015/Aug/msg00001.html
• http://lists.fedoraproject.org/pipermail/package-announce/2015-August/165170.htm
• http://lists.fedoraproject.org/pipermail/package-announce/2015-July/162955.html
• http://lists.opensuse.org/opensuse-security-announce/2015-09/msg00017.html
• http://openwall.com/lists/oss-security/2015/07/23/4
• http://rhn.redhat.com/errata/RHSA-2016-0466.html
• http://seclists.org/fulldisclosure/2015/Jul/92Exploit
• http://www.oracle.com/technetwork/security-advisory/cpujul2016-2881720.html
• http://www.oracle.com/technetwork/security-advisory/cpujul2018-4258247.html
• http://www.oracle.com/technetwork/topics/security/bulletinoct2015-2511968.html
• http://www.oracle.com/technetwork/topics/security/linuxbulletinapr2016-2952096.h
• http://www.oracle.com/technetwork/topics/security/linuxbulletinoct2015-2719645.h