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Fencer Intel
high 7.5

CVE-2016-8858 in the critical feed json

The kex_input_kexinit function in kex.c in OpenSSH 6.x and 7.x through 7.3 allows remote attackers to cause a denial of service (memory con…

published 2016-12-09 9 y ago modified 2026-06-17 4 mo ago also EUVD-2016-9683

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
29.5%
EPSS 29.5% chance of exploitation in 30 days, percentile 98%
public exploits
0
none known

Summary

The kex_input_kexinit function in kex.c in OpenSSH 6.x and 7.x through 7.3 allows remote attackers to cause a denial of service (memory consumption) by sending many duplicate KEXINIT requests. NOTE: a third party reports that "OpenSSH upstream does not consider this as a security issue."

Patch / fix

  • openssh Debian 14, Debian 13, Debian 12 1:7.3p1-2

debian advisories DEBIAN-CVE-2016-8858

  • openssh-openssl1 SLES 11-SECURITY 6.6p1-18.1
  • openssh SLES 12 SP1, SLED 12 SP1, SLES for SAP 12 SP1 +2 more 6.6p1-54.7.1
  • openssh-askpass-gnome SLES 12 SP1, SLED 12 SP1, SLES for SAP 12 SP1 +2 more 6.6p1-54.7.1
  • openssh SLES 11 SP3-TERADATA, SLES 11 SP3-LTSS, SLE Point of Sale 11 SP3 +3 more 6.2p2-0.40.1
  • openssh-askpass-gnome SLES 11 SP3-TERADATA, SLES 11 SP3-LTSS, SLE Point of Sale 11 SP3 +3 more 6.2p2-0.40.3
  • openssh SLES for SAP 11 SP4, SLES 11 SP4 6.6p1-35.1
  • openssh-askpass-gnome SLES for SAP 11 SP4, SLES 11 SP4 6.6p1-35.4
  • openssh SLES for SAP 12 SP2, SLES for Raspberry Pi 12 SP2, SLES 12 SP2 +1 more 7.2p2-66.1

suse advisories SUSE-SU-2017:1661-1SUSE-SU-2017:0607-1SUSE-SU-2017:0607-2SUSE-SU-2017:0607-3SUSE-SU-2017:0606-1SUSE-SU-2017:0603-1

  • openssh openSUSE Tumbleweed 8.4p1-7.4

opensuse advisories openSUSE-SU-2024:11124-1

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-2016-8858 updated cvss 5.8

openssh: Memory exhaustion due to unregistered KEXINIT handler after receiving message

  • Red Hat Enterprise Linux 5 openssh Red Hat Enterprise Linux 6 openssh, openssh-ldap, openssh-server, openssh-askpass, openssh-clients, pam_ssh_agent_auth Red Hat Enterprise Linux 7 openssh, openssh-cavs, openssh-ldap, openssh-keycat, openssh-server, openssh-askpass, +3 more
    not affected: vulnerable code not present

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

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
2 y ago

Exploit prediction

29.46% chance of exploitation in the next 30 days, higher than 98% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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-400 Uncontrolled Resource Consumption
  • CWE-399 Resource Management Errors

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.