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Fencer Intel
high 7.5

CVE-2016-6515 in the critical feed json

The auth_password function in auth-passwd.c in sshd in OpenSSH before 7.3 does not limit password lengths for password authentication, whic…

published 2016-08-07 10 y ago modified 2026-06-17 4 mo ago also EUVD-2016-7437

cvss
7.5
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
58.6%
EPSS 58.6% chance of exploitation in 30 days, percentile 99.1%
public exploits
1
Exploit-DB

Summary

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.

Patch / fix

  • openssh Debian 14, Debian 13, Debian 12 1:7.3p1-1

debian advisories DEBIAN-CVE-2016-6515

  • openssh Ubuntu 14.04 LTS 1:6.6p1-2ubuntu2.8
  • openssh Ubuntu 16.04 LTS 1:7.2p2-4ubuntu2.1

ubuntu advisories UBUNTU-CVE-2016-6515

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • openssh RHEL 7 7.4p1-11.el7
  • openssh-cavs RHEL 7 7.4p1-11.el7
  • openssh-ldap RHEL 7 7.4p1-11.el7
  • openssh-keycat RHEL 7 7.4p1-11.el7
  • openssh-server RHEL 7 7.4p1-11.el7
  • openssh-askpass RHEL 7 7.4p1-11.el7
  • openssh-clients RHEL 7 7.4p1-11.el7
  • pam_ssh_agent_auth RHEL 7 0.10.3-1.11.el7

red hat advisories RHSA-2017:2029

  • openssh-openssl1 SLES 11-SECURITY 6.6p1-15.1
  • openssh SLES 11 SP3-TERADATA, SLES 11 SP3-LTSS, SLE Point of Sale 11 SP3 +3 more 6.2p2-0.33.2
  • openssh-askpass-gnome SLES 11 SP3-TERADATA, SLES 11 SP3-LTSS, SLE Point of Sale 11 SP3 +3 more 6.2p2-0.33.5
  • openssh SLES for SAP 11 SP4, SLES 11 SP4 6.6p1-28.1
  • openssh-askpass-gnome SLES for SAP 11 SP4, SLES 11 SP4 6.6p1-28.2
  • openssh SLES for SAP 12 SP1, SLES for SAP 12, SLES 12-LTSS +2 more 6.6p1-52.1
  • openssh-askpass-gnome SLES for SAP 12 SP1, SLES for SAP 12, SLES 12-LTSS +2 more 6.6p1-52.1

suse advisories SUSE-SU-2016:2555-1SUSE-SU-2016:2388-1SUSE-SU-2016:2281-1SUSE-SU-2016:2280-1

  • openssh openSUSE Tumbleweed 7.2p2-3.1

opensuse advisories openSUSE-SU-2024:10174-1

  • openssh Alpine 3.2 6.8_p1-r8
  • openssh Alpine 3.4, Alpine 3.3 7.2_p2-r2

alpine advisories ALPINE-CVE-2016-6515

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2016-6515 updated cvss 5.3

openssh: Denial of service via very long passwords

  • Red Hat Enterprise Linux 5 openssh Red Hat Enterprise Linux 6 openssh, openssh-ldap, openssh-server, openssh-askpass, openssh-clients, pam_ssh_agent_auth
    affected: no fix planned “Will not fix”
  • Red Hat Enterprise Linux Client (v. 7) openssh 7.4p1-11.el7, openssh-keycat 7.4p1-11.el7, openssh-server 7.4p1-11.el7, openssh-askpass 7.4p1-11.el7, openssh-clients 7.4p1-11.el7 Red Hat Enterprise Linux Client Optional (v. 7) openssh-cavs 7.4p1-11.el7, openssh-ldap 7.4p1-11.el7, pam_ssh_agent_auth 0.10.3-1.11.el7, openssh-server-sysvinit 7.4p1-11.el7 Red Hat Enterprise Linux ComputeNode (v. 7) openssh 7.4p1-11.el7, openssh-keycat 7.4p1-11.el7, openssh-server 7.4p1-11.el7, openssh-clients 7.4p1-11.el7 Red Hat Enterprise Linux ComputeNode Optional (v. 7) openssh-cavs 7.4p1-11.el7, openssh-ldap 7.4p1-11.el7, openssh-askpass 7.4p1-11.el7, pam_ssh_agent_auth 0.10.3-1.11.el7, openssh-server-sysvinit 7.4p1-11.el7 Red Hat Enterprise Linux Server (v. 7) openssh 7.4p1-11.el7, openssh-keycat 7.4p1-11.el7, openssh-server 7.4p1-11.el7, openssh-askpass 7.4p1-11.el7, openssh-clients 7.4p1-11.el7 Red Hat Enterprise Linux Server Optional (v. 7) openssh-cavs 7.4p1-11.el7, openssh-ldap 7.4p1-11.el7, pam_ssh_agent_auth 0.10.3-1.11.el7, openssh-server-sysvinit 7.4p1-11.el7
    +2 more products
    Red Hat Enterprise Linux Workstation (v. 7) openssh 7.4p1-11.el7, openssh-keycat 7.4p1-11.el7, openssh-server 7.4p1-11.el7, openssh-askpass 7.4p1-11.el7, openssh-clients 7.4p1-11.el7 Red Hat Enterprise Linux Workstation Optional (v. 7) openssh-cavs 7.4p1-11.el7, openssh-ldap 7.4p1-11.el7, pam_ssh_agent_auth 0.10.3-1.11.el7, openssh-server-sysvinit 7.4p1-11.el7
    fixed: vendor fix RHSA-2017:2029

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

cisa ICSA-22-349-21 updated cvss 7.5

Siemens SCALANCE X-200RNA Switch Devices

  • Siemens SCALANCE X204RNA (HSR) (6GK5204-0BA00-2MB2) <V3.2.7 Siemens SCALANCE X204RNA (PRP) (6GK5204-0BA00-2KB2) <V3.2.7 Siemens SCALANCE X204RNA EEC (HSR) (6GK5204-0BS00-2NA3) <V3.2.7 Siemens SCALANCE X204RNA EEC (PRP) (6GK5204-0BS00-3LA3) <V3.2.7 Siemens SCALANCE X204RNA EEC (PRP/HSR) (6GK5204-0BS00-3PA3) <V3.2.7
    affected: fixed in V3.2.7, mitigation support.industry.siemens.com

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

Timeline

  1. Published
  2. First public exploit (EDB-40888)

Exploit prediction

58.57% chance of exploitation in the next 30 days, higher than 99.1% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • EDB-40888 OpenSSH 7.2 - Denial of Service dos, 2016-12-07

CVSS scores

assigned by version score vector
NVD 3.0 7.5 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 7.8 AV:N/AC:L/Au:N/C:N/I:N/A:C

Classification

Weakness
  • CWE-20 Improper Input Validation

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.