What’s Vulnerable › Vulnerabilities

CVE-2016-6515

• Severity: high (CVSS 7.5 v3.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 58.6% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2016-08-07 · updated 2026-06-17
• Weakness: CWE-20

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.

Affected products

• Fedoraproject Fedora: 24
• OpenSSH: through 7.2

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

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