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Fencer Vulns
high 8.1

CVE-2024-6387 in the critical feed json

Openssh: regresshion - race condition in ssh allows rce/dos

published 2024-07-01 2 y ago modified 2026-11-06 2 d ago also EUVD-2024-47981 , JLSEC-2026-71

cvss
8.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
99.5%
EPSS 99.5% chance of exploitation in 30 days, percentile 99.9%
public exploits
1
Exploit-DB

Summary

A security regression (CVE-2006-5051) was discovered in OpenSSH's server (sshd). There is a race condition which can lead sshd to handle some signals in an unsafe manner. An unauthenticated, remote attacker may be able to trigger it by failing to authenticate within a set time period.

Patch / fix

  • julia OpenSSH_jll 9.9.1+0
  • Red Hat Red Hat Enterprise Linux 9 0:8.7p1-38.el9_4.1
  • Red Hat Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions 0:8.7p1-12.el9_0.1
  • Red Hat Red Hat Enterprise Linux 9.2 Extended Update Support 0:8.7p1-30.el9_2.4
  • Red Hat Red Hat OpenShift Container Platform 4.13 413.92.202407091321-0
  • Red Hat Red Hat OpenShift Container Platform 4.14 414.92.202407091253-0
  • Red Hat Red Hat OpenShift Container Platform 4.15 415.92.202407091355-0
  • Red Hat Red Hat OpenShift Container Platform 4.16 416.94.202407081958-0
  • Siemens SINAMICS IIoT module V1.0 HF1
  • Siemens SINEMA Remote Connect Server V3.2 SP2
  • Siemens SINUMERIK ONE V6.24
  • openssh Debian 12 1:9.2p1-2+deb12u3
  • openssh Debian 14, Debian 13 1:9.7p1-7

debian advisories DEBIAN-CVE-2024-6387

  • openssh Ubuntu 22.04 LTS 1:8.9p1-3ubuntu0.10
  • openssh Ubuntu 24.04 LTS 1:9.6p1-3ubuntu13.3

ubuntu advisories UBUNTU-CVE-2024-6387

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 9 8.7p1-38.el9_4.1
  • openssh-keycat RHEL 9 8.7p1-38.el9_4.1
  • openssh-server RHEL 9 8.7p1-38.el9_4.1
  • openssh-askpass RHEL 9 8.7p1-38.el9_4.1
  • openssh-clients RHEL 9 8.7p1-38.el9_4.1
  • pam_ssh_agent_auth RHEL 9 0.10.4-5.38.el9_4.1
  • openssh RHEL 9.0 E4S 8.7p1-12.el9_0.1
  • openssh-keycat RHEL 9.0 E4S 8.7p1-12.el9_0.1

red hat advisories RHSA-2024:4389RHSA-2024:4340RHSA-2024:4312

  • openssh Linux Micro 6.0 9.6p1-2.1
  • openssh SLE Module for Basesystem 15 SP6, openSUSE Leap 15.6 9.6p1-150600.6.3.1
  • openssh-askpass-gnome SLE Module for Desktop Applications 15 SP6, openSUSE Leap 15.6 9.6p1-150600.6.3.1

suse advisories SUSE-SU-2025:20009-1SUSE-SU-2024:2275-1SUSE-SU-2024:2275-2

  • openssh openSUSE Tumbleweed 9.6p1-10.1

opensuse advisories openSUSE-SU-2024:14088-1

  • openssh AlmaLinux 9 8.7p1-38.el9_4.1
  • openssh-keycat AlmaLinux 9 8.7p1-38.el9_4.1
  • openssh-server AlmaLinux 9 8.7p1-38.el9_4.1
  • openssh-askpass AlmaLinux 9 8.7p1-38.el9_4.1
  • openssh-clients AlmaLinux 9 8.7p1-38.el9_4.1
  • pam_ssh_agent_auth AlmaLinux 9 0.10.4-5.38.el9_4.1

almalinux advisories ALSA-2024:4312

  • openssh Alpine 3.17 9.1_p1-r6
  • openssh Alpine 3.18 9.3_p2-r2
  • openssh Alpine 3.19 9.6_p1-r1
  • openssh Alpine 3.20 9.7_p1-r4
  • openssh Alpine 3.24, Alpine 3.23, Alpine 3.22 +1 more 9.8_p1-r0

alpine advisories ALPINE-CVE-2024-6387

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

  • openssh Azure Linux 3.0 9.8p1-1
  • openssh CBL-Mariner 2.0 8.9p1-6

azure linux advisories AZL-43024AZL-43030

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

  • openssh Arch Linux 9.8p1-1

arch linux advisories AVG-2855

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-2024-6387 updated cvss 8.1

openssh: regreSSHion - race condition in SSH allows RCE/DoS

  • Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8
    affected: workaround, no fix planned “Will not fix”
  • Red Hat Enterprise Linux AppStream (v. 9) openssh-askpass 8.7p1-38.el9_4.1, pam_ssh_agent_auth 0.10.4-5.38.el9_4.1
    fixed: vendor fix RHSA-2024:4312
  • Red Hat Enterprise Linux AppStream E4S (v.9.0) openssh-askpass 8.7p1-12.el9_0.1, pam_ssh_agent_auth 0.10.4-4.12.el9_0.1
    fixed: vendor fix RHSA-2024:4389
  • Red Hat Enterprise Linux AppStream EUS (v.9.2) openssh-askpass 8.7p1-30.el9_2.4, pam_ssh_agent_auth 0.10.4-5.30.el9_2.4
    fixed: vendor fix RHSA-2024:4340
  • Red Hat Enterprise Linux BaseOS (v. 9) openssh 8.7p1-38.el9_4.1, openssh-keycat 8.7p1-38.el9_4.1, openssh-server 8.7p1-38.el9_4.1, openssh-clients 8.7p1-38.el9_4.1
    fixed: vendor fix RHSA-2024:4312
  • Red Hat Enterprise Linux BaseOS E4S (v.9.0) openssh 8.7p1-12.el9_0.1, openssh-keycat 8.7p1-12.el9_0.1, openssh-server 8.7p1-12.el9_0.1, openssh-clients 8.7p1-12.el9_0.1
    fixed: vendor fix RHSA-2024:4389
  • Red Hat Enterprise Linux BaseOS EUS (v.9.2) openssh 8.7p1-30.el9_2.4, openssh-keycat 8.7p1-30.el9_2.4, openssh-server 8.7p1-30.el9_2.4, openssh-clients 8.7p1-30.el9_2.4
    fixed: vendor fix RHSA-2024:4340
  • Red Hat OpenShift Container Platform 4.13 rhcos 413.92.202407091321-0
    fixed: vendor fix RHSA-2024:4484
show 4 more
  • Red Hat OpenShift Container Platform 4.14 rhcos 414.92.202407091253-0
    fixed: vendor fix RHSA-2024:4479
  • Red Hat OpenShift Container Platform 4.15 rhcos 415.92.202407091355-0
    fixed: vendor fix RHSA-2024:4474
  • Red Hat OpenShift Container Platform 4.16 rhcos 416.94.202407081958-0
    fixed: vendor fix RHSA-2024:4469
  • Red Hat Ceph Storage 5 openssh Red Hat Ceph Storage 6 openssh Red Hat Ceph Storage 7 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 Red Hat Enterprise Linux 8 openssh, openssh-cavs, openssh-ldap, openssh-keycat, openssh-server, openssh-askpass, +2 more
    +5 more products
    Red Hat Enterprise Linux 10 openssh Red Hat OpenShift Container Platform 4.13 openshift4/ose-cli v4.13.0-202407081338.p0.gd192e90.assembly.stream.el8, openshift4/ose-pod v4.13.0-202407081338.p0.g4818370.assembly.stream.el8, openshift4/ose-tests v4.13.0-202407081338.p0.g36ca5dc.assembly.stream.el8, openshift4/ose-console v4.13.0-202407081338.p0.gdc7be0c.assembly.stream.el8, openshift4/ose-coredns v4.13.0-202407081338.p0.g298d919.assembly.stream.el8, openshift4/ose-deployer v4.13.0-202407081338.p0.gd192e90.assembly.stream.el8, +186 more Red Hat OpenShift Container Platform 4.14 openshift4/ose-tests v4.14.0-202407101510.p0.ga9a03be.assembly.stream.el8, openshift4/ose-console v4.14.0-202407101709.p0.geb981dc.assembly.stream.el8, openshift4/ose-prometheus v4.14.0-202407080910.p0.gb7c61bc.assembly.stream.el8, openshift4/ose-ironic-rhel9 v4.14.0-202407091409.p0.gd732a6b.assembly.stream.el9, openshift4/ose-thanos-rhel8 v4.14.0-202407080910.p0.ga267125.assembly.stream.el8, openshift4/ose-docker-builder v4.14.0-202407080910.p0.g9c104de.assembly.stream.el8, +30 more Red Hat OpenShift Container Platform 4.15 openshift4/ose-tests v4.15.0-202407100607.p0.g5f9656e.assembly.stream.el8, openshift4/ose-console v4.15.0-202407101638.p0.g4cb2052.assembly.stream.el8, openshift4/ose-installer v4.15.0-202407041041.p0.gfe35ee5.assembly.stream.el8, openshift4/ose-pod-rhel9 v4.15.0-202407080939.p0.gadd48d0.assembly.stream.el9, openshift4/ose-sdn-rhel9 v4.15.0-202407080939.p0.g71a6f28.assembly.stream.el9, openshift4/ose-etcd-rhel9 v4.15.0-202407080939.p0.ga7005ef.assembly.stream.el9, +146 more Red Hat OpenShift Container Platform 4.16 openshift4/ose-cli-rhel9 v4.16.0-202407081937.p0.g0127eb4.assembly.stream.el9, openshift4/ose-pod-rhel9 v4.16.0-202407031636.p0.gaba1e8d.assembly.stream.el9, openshift4/ose-sdn-rhel9 v4.16.0-202407081937.p0.g5b658c4.assembly.stream.el9, openshift4/ose-etcd-rhel9 v4.16.0-202407031636.p0.gbc2fec2.assembly.stream.el9, openshift4/ose-tests-rhel9 v4.16.0-202407091806.p0.gac6867d.assembly.stream.el9, openshift4/ose-tools-rhel9 v4.16.0-202407091337.p0.g0127eb4.assembly.stream.el9, +184 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-25-162-05 updated cvss 8.1

Siemens SIMATIC S7-1500 CPU family

  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) >= 3.1.5 Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) >= 3.1.5 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) >= 3.1.5 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0) >= 3.1.5 Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0) >= 3.1.5
    affected: mitigation, no fix available

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

cisa ICSA-24-256-15 updated cvss 8.1

Siemens Industrial Products

  • Siemens Industrial Edge Management OS (IEM-OS)
    affected: mitigation, no fix planned
  • Siemens SINAMICS IIoT module <V1.0_HF1
    affected: fixed in V1.0, mitigation support.industry.siemens.com
  • Siemens SINEMA Remote Connect Server <V3.2_SP2
    affected: fixed in V3.2, mitigation support.industry.siemens.com
  • Siemens SINUMERIK ONE < V6.24
    affected: fixed in V6.24, mitigation

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

cisa ICSA-25-100-09 updated cvss 8.1

ABB Arctic Wireless Gateways

  • ABB Arctic ARG600, ARC600, ARR600, ARP600
    affected: mitigation

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-52269)

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
total
Assessed
2 y ago

Exploit prediction

99.51% chance of exploitation in the next 30 days, higher than 99.9% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • EDB-52269 OpenSSH server (sshd) 9.8p1 - Race Condition remote, 2025-04-22
  • santandersecurityresearch.github.io https://santandersecurityresearch.github.io/blog/sshing_the_masses.html referenced PoC, tagged "exploit" by a source, unverified
  • qualys.com https://www.qualys.com/2024/07/01/cve-2024-6387/regresshion.txt referenced PoC, tagged "exploit" by a source, unverified
  • vicarius.io https://www.vicarius.io/vsociety/posts/regresshion-an-openssh-regression-error-cve-2024-6387 referenced PoC, tagged "exploit" by a source, unverified
  • openwall.com http://www.openwall.com/lists/oss-security/2024/07/03/11 referenced PoC, tagged "exploit" by a source, unverified
  • openwall.com http://www.openwall.com/lists/oss-security/2024/07/04/2 referenced PoC, tagged "exploit" by a source, unverified
  • openwall.com http://www.openwall.com/lists/oss-security/2024/07/08/2 referenced PoC, tagged "exploit" by a source, unverified
  • openwall.com http://www.openwall.com/lists/oss-security/2024/07/09/5 referenced PoC, tagged "exploit" by a source, unverified
  • openwall.com http://www.openwall.com/lists/oss-security/2024/07/10/1 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
OSV 3.1 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
julia OpenSSH_jll
>=8.9.0+0, <9.9.1+0
9.9.1+0

Affected products

  • Red Hat Red Hat Enterprise Linux 9
  • Red Hat Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions
  • Red Hat Red Hat Enterprise Linux 9.2 Extended Update Support
  • Red Hat Red Hat OpenShift Container Platform 4.13
  • Red Hat Red Hat OpenShift Container Platform 4.14
  • Red Hat Red Hat OpenShift Container Platform 4.15
  • Red Hat Red Hat OpenShift Container Platform 4.16
  • Red Hat Red Hat Ceph Storage 5
  • Red Hat Red Hat Ceph Storage 6
  • Red Hat Red Hat Ceph Storage 7
  • Red Hat Red Hat Enterprise Linux 10
  • Red Hat Red Hat Enterprise Linux 6
  • Red Hat Red Hat Enterprise Linux 7
  • Red Hat Red Hat Enterprise Linux 8
  • Red Hat Red Hat OpenShift Container Platform 4
  • Siemens Industrial Edge Management OS (IEM-OS)
  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP
  • Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP
  • Siemens SINAMICS IIoT module
  • Siemens SINEMA Remote Connect Server
  • Siemens SINUMERIK ONE
  • Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP

Classification

Weakness
  • CWE-364 Signal Handler Race Condition
  • CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization

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.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.