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Fencer Vulns
medium 5.9

CVE-2020-14145 json

The client side in OpenSSH 5.7 through 8.4 has an Observable Discrepancy leading to an information leak in the algorithm negotiation.

published 2020-06-29 6 y ago modified 2026-10-14 26 d ago also EUVD-2020-6303 , JLSEC-2026-63

cvss
5.9
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
2.9%
EPSS 2.9% chance of exploitation in 30 days, percentile 87%
public exploits
0
none known

Summary

The client side in OpenSSH 5.7 through 8.4 has an Observable Discrepancy leading to an information leak in the algorithm negotiation. This allows man-in-the-middle attackers to target initial connection attempts (where no host key for the server has been cached by the client). NOTE: some reports state that 8.5 and 8.6 are also affected.

Patch / fix

  • julia OpenSSH_jll 9.1.0+0
  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP V3.1.5
  • Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP V3.1.5
  • Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP V3.1.5
  • openssh RHEL 8 8.0p1-10.el8
  • openssh-cavs RHEL 8 8.0p1-10.el8
  • openssh-ldap RHEL 8 8.0p1-10.el8
  • openssh-keycat RHEL 8 8.0p1-10.el8
  • openssh-server RHEL 8 8.0p1-10.el8
  • openssh-askpass RHEL 8 8.0p1-10.el8
  • openssh-clients RHEL 8 8.0p1-10.el8
  • pam_ssh_agent_auth RHEL 8 0.10.3-7.10.el8

red hat advisories RHSA-2021:4368

  • openssh SLES for SAP 12 SP3, SLES for SAP 12 SP2, SLES 12 SP3-LTSS +8 more 7.2p2-74.57.1
  • openssh-askpass-gnome SLES for SAP 12 SP3, SLES for SAP 12 SP2, SLES 12 SP3-LTSS +8 more 7.2p2-74.57.1
  • openssh SLES for SAP 15, SLES 15-LTSS, SLE High Performance Computing 15-LTSS +1 more 7.6p1-9.38.1
  • openssh SLE Module for Server Applications 15 SP1, SLE Module for Basesystem 15 SP1 7.9p1-6.22.1
  • openssh-askpass-gnome SLE Module for Desktop Applications 15 SP1 7.9p1-6.22.1
  • openssh SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES 12 SP5 +3 more 7.2p2-78.10.1
  • openssh-askpass-gnome SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES 12 SP5 +3 more 7.2p2-78.10.1
  • openssh SLE Module for Server Applications 15 SP2, SLE Module for Basesystem 15 SP2 8.1p1-5.9.1

suse advisories SUSE-SU-2021:0022-1SUSE-SU-2020:3882-1SUSE-SU-2020:3866-1SUSE-SU-2020:3844-1SUSE-SU-2020:3736-1

  • openssh openSUSE Leap 15.1 7.9p1-lp151.4.18.1
  • openssh-askpass-gnome openSUSE Leap 15.1 7.9p1-lp151.4.18.1
  • openssh openSUSE Leap 15.2 8.1p1-lp152.4.9.1
  • openssh-askpass-gnome openSUSE Leap 15.2 8.1p1-lp152.4.9.1

opensuse advisories openSUSE-SU-2020:2298-1openSUSE-SU-2020:2240-1

  • openssh-askpass AlmaLinux 8 8.0p1-10.el8

almalinux advisories ALSA-2021:4368

  • openssh Rocky Linux 8 8.0p1-10.el8

rocky linux advisories RLSA-2021:4368

  • openssh Alpine 3.12 8.3_p1-r1
  • openssh Alpine 3.24, Alpine 3.23, Alpine 3.22 +9 more 8.4_p1-r0

alpine advisories ALPINE-CVE-2020-14145

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-2020-14145 updated cvss 5.9

openssh: Observable discrepancy leading to an information leak in the algorithm negotiation

  • 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
    affected: workaround, no fix planned “Always connect to SSH servers with verified host keys to avoid any possibilities of man-in-the-middle attack.”
  • Red Hat Enterprise Linux AppStream (v. 8) openssh-askpass 8.0p1-10.el8 Red Hat Enterprise Linux BaseOS (v. 8) openssh 8.0p1-10.el8, openssh-cavs 8.0p1-10.el8, openssh-ldap 8.0p1-10.el8, openssh-keycat 8.0p1-10.el8, openssh-server 8.0p1-10.el8, openssh-clients 8.0p1-10.el8, +1 more
    fixed: vendor fix “Always connect to SSH servers with verified host keys to avoid any possibilities of man-in-the-middle attack.” RHSA-2021:4368

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-23-348-10 updated cvss 5.9

Siemens SIMATIC S7-1500

  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) >= 3.1.0, < 3.1.5 Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) >= 3.1.0, < 3.1.5 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) >= 3.1.0, < 3.1.5 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0) >= 3.1.0, < 3.1.5 Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0) >= 3.1.0, < 3.1.5
    affected: fixed in V3.1.5, 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
no
Technical impact
partial
Assessed
10 mo ago

Exploit prediction

2.95% chance of exploitation in the next 30 days, higher than 87% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
CNA 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:P/I:N/A:N
OSV 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected packages

ecosystem package affected fixed in
julia OpenSSH_jll
<9.1.0+0
9.1.0+0

Affected products

  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP
  • Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP
  • Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP

Classification

Weakness

References

Sources

Fencer Vulns 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.