CVE-2016-6515 EXPLOIT
7.5
HIGH · CVSS 3.0 · EPSS 58.6% (pctl 99)
Patch early
A public exploit exists.
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.
Scoring
| CVSS | 7.5 (HIGH, v3.0) |
|---|---|
| Vector | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| EPSS | 58.57% — more likely to be exploited than 99% of all CVEs |
| Weakness | CWE-20 |
| On CISA KEV | no |
| Public exploit | yes |
| Published | 2016-08-07 |
| Last modified | 2026-06-17 |
Affected (2)
| Vendor | Product |
|---|---|
| fedoraproject | fedora |
| openbsd | openssh |
Public exploits
| Source | Title | Date |
|---|---|---|
| exploit-db | OpenSSH 7.2 - Denial of Service | 2016-12-07 |
References
- http://openwall.com/lists/oss-security/2016/08/01/2
- http://packetstormsecurity.com/files/140070/OpenSSH-7.2-Denial-Of-Service.html
- http://www.oracle.com/technetwork/security-advisory/cpuoct2017-3236626.html
- http://www.securityfocus.com/bid/92212
- http://www.securitytracker.com/id/1036487
- https://access.redhat.com/errata/RHSA-2017:2029
- https://cert-portal.siemens.com/productcert/pdf/ssa-412672.pdf
- https://cert-portal.siemens.com/productcert/pdf/ssa-676336.pdf
- https://github.com/openssh/openssh-portable/commit/fcd135c9df440bcd2d5870405ad3311743d78d97
- https://lists.debian.org/debian-lts-announce/2018/09/msg00010.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/X2L6RW34VFNXYNVVN2CN73YAGJ5VMTFU/
- https://security.FreeBSD.org/advisories/FreeBSD-SA-17:06.openssh.asc
- https://security.netapp.com/advisory/ntap-20171130-0003/
- https://support.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbhf03779en_us
- https://www.exploit-db.com/exploits/40888/
- http://openwall.com/lists/oss-security/2016/08/01/2
- http://packetstormsecurity.com/files/140070/OpenSSH-7.2-Denial-Of-Service.html
- http://www.oracle.com/technetwork/security-advisory/cpuoct2017-3236626.html
- http://www.securityfocus.com/bid/92212
- http://www.securitytracker.com/id/1036487
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