The kbdint_next_device function in auth2-chall.c in sshd in OpenSSH through 6.9 does not properly restrict the processing of…

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.

Scores

EPSS (exploitation in 30 days)

9.4% · top 4.6% of all CVEs (4 Nov 2026)

CISA SSVC

Exploitation: none · Automatable: no · Technical impact: total

The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.1.

Weakness

• n/a
• CWE-400 Uncontrolled Resource Consumption (opens in a new tab)All about CWE-400 and its CVEs
• CWE-264 (opens in a new tab)All about CWE-264 and its CVEs

Affected products

• n/a

  • affected n/a

References (33)

• http://www.oracle.com/technetwork/topics/security/ovmbulletinjul2016-3090546.html (opens in a new tab)x_transferred
• USN-2710-2 (opens in a new tab)vendor-advisoryx_transferred
• FEDORA-2015-13469 (opens in a new tab)vendor-advisoryx_transferred
• http://www.oracle.com/technetwork/security-advisory/cpujul2018-4258247.html (opens in a new tab)x_transferred
• https://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05157667 (opens in a new tab)x_transferred
• https://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05128992 (opens in a new tab)x_transferred
• http://www.oracle.com/technetwork/topics/security/linuxbulletinapr2016-2952096.html (opens in a new tab)x_transferred
• http://www.oracle.com/technetwork/security-advisory/cpujul2016-2881720.html (opens in a new tab)x_transferred
• GLSA-201512-04 (opens in a new tab)vendor-advisoryx_transferred
• https://kc.mcafee.com/corporate/index?page=content&id=SB10136 (opens in a new tab)x_transferred
• https://security.netapp.com/advisory/ntap-20151106-0001/ (opens in a new tab)x_transferred
• RHSA-2016:0466 (opens in a new tab)vendor-advisoryx_transferred
• http://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/auth2-chall.c.diff?r1=1.42&r2=1.43&f=h (opens in a new tab)x_transferred
• http://www.oracle.com/technetwork/topics/security/linuxbulletinoct2015-2719645.html (opens in a new tab)x_transferred
• http://kb.juniper.net/InfoCenter/index?page=content&id=JSA10697 (opens in a new tab)x_transferred
• APPLE-SA-2015-08-13-2 (opens in a new tab)vendor-advisoryx_transferred
• http://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/auth2-chall.c (opens in a new tab)x_transferred
• https://kc.mcafee.com/corporate/index?page=content&id=SB10157 (opens in a new tab)x_transferred
• 75990 (opens in a new tab)vdb-entryx_transferred
• 91787 (opens in a new tab)vdb-entryx_transferred
• https://h20564.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c04952480 (opens in a new tab)x_transferred
• SUSE-SU-2015:1581 (opens in a new tab)vendor-advisoryx_transferred
• 92012 (opens in a new tab)vdb-entryx_transferred
• https://support.apple.com/kb/HT205031 (opens in a new tab)x_transferred
• [debian-lts-announce] 20180910 [SECURITY] [DLA 1500-1] openssh security update (opens in a new tab)mailing-listx_transferred
• [oss-security] 20150723 Re: CVE Request for OpenSSH vulnerability - authentication limits bypass (opens in a new tab)mailing-listx_transferred
• USN-2710-1 (opens in a new tab)vendor-advisoryx_transferred
• FEDORA-2015-11981 (opens in a new tab)vendor-advisoryx_transferred
• 1032988 (opens in a new tab)vdb-entryx_transferred
• 20150717 OpenSSH keyboard-interactive authentication brute force vulnerability (MaxAuthTries bypass) (opens in a new tab)mailing-listx_transferred
• http://www.oracle.com/technetwork/topics/security/bulletinoct2015-2511968.html (opens in a new tab)x_transferred
• https://www.arista.com/en/support/advisories-notices/security-advisories/1174-security-advisory-12 (opens in a new tab)x_transferred
• https://cert-portal.siemens.com/productcert/pdf/ssa-412672.pdf (opens in a new tab)x_transferred

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2015-5600](https://trackcve.app/badge/CVE-2015-5600.svg)](https://trackcve.app/cve/CVE-2015-5600)

Record last updated 27 May 2026, 16:31 UTC.