CVE-2015-5600
HIGH severity · CVSS 8.1 · CWE-264
8.1CVSS HIGH
Summary
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.
Impact & exploitability
Attack vectorNetwork
Attack complexityHigh
Privileges requiredNone
User interactionNone
Confidentiality impactHigh
Integrity impactHigh
Availability impactHigh
Exploit probability (EPSS)9%
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Affected products we track (1)
Recommendation
Apply the vendor fix promptly. Open any affected product above for its exact safe version.
Additional information
- NVD record
- 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=1.42&r2=1.43&f=h
- 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.html
- 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