CVE-2016-6515

Public Exploit

Description

The auth_password function in auth-passwd.c in sshd in OpenSSH before 7.3 does not limit password lengths for password authentication, which allows remote attackers to cause a denial of service (crypt CPU consumption) via a long string.

Category

7.5
CVSS
Severity: High
CVSS 3.0 •
CVSS 2.0 •
EPSS 84.41% Top 5%
Vendor Advisory FreeBSD.org Vendor Advisory fedoraproject.org Vendor Advisory redhat.com
Affected: n/a n/a
Published at:
Updated at:

References

Link Tags
https://support.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbhf03779en_us
https://security.netapp.com/advisory/ntap-20171130-0003/
https://github.com/openssh/openssh-portable/commit/fcd135c9df440bcd2d5870405ad3311743d78d97 patch issue tracking
http://packetstormsecurity.com/files/140070/OpenSSH-7.2-Denial-Of-Service.html
https://www.exploit-db.com/exploits/40888/ exploit
http://www.securityfocus.com/bid/92212 vdb entry
https://security.FreeBSD.org/advisories/FreeBSD-SA-17:06.openssh.asc vendor advisory
http://www.oracle.com/technetwork/security-advisory/cpuoct2017-3236626.html
http://www.securitytracker.com/id/1036487 vdb entry
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/X2L6RW34VFNXYNVVN2CN73YAGJ5VMTFU/ vendor advisory
https://access.redhat.com/errata/RHSA-2017:2029 vendor advisory
https://lists.debian.org/debian-lts-announce/2018/09/msg00010.html mailing list
http://openwall.com/lists/oss-security/2016/08/01/2 mailing list third party advisory vdb entry
https://cert-portal.siemens.com/productcert/pdf/ssa-676336.pdf
https://cert-portal.siemens.com/productcert/pdf/ssa-412672.pdf

Frequently Asked Questions

What is the severity of CVE-2016-6515?
CVE-2016-6515 has been scored as a high severity vulnerability.
How to fix CVE-2016-6515?
To fix CVE-2016-6515, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2016-6515 being actively exploited in the wild?
It is possible that CVE-2016-6515 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~84% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
This platform uses data from the NIST NVD, MITRE CVE, MITRE CWE, First.org and CISA KEV but is not endorsed or certified by these entities. CVE is a registred trademark of the MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. CWE is a registred trademark of the MITRE Corporation and the authoritative source of CWE content is MITRE's CWE web site.
© 2025 Under My Watch. All Rights Reserved.