high
8.1
CWE
362 364 20 190 119
EPSS
71.475%
Advisory Published
CVE Published
Advisory Published
Advisory Published
Updated

CVE-2024-6387: OpenSSH regreSSHion Attack (CVE-2024-6387)

First published: Thu Jun 27 2024(Updated: )

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.

Credit: CVE-2024-6387 CertiK SkyFall Team sqrtpwn Minghao Lin Zhejiang UniversityJiaxun Zhu Zhejiang UniversityPatrick Wardle DoubleYouCVE-2024-40805 Rodolphe BRUNETTI @eisw0lf Adam M. Mickey Jin @patch1t Zhongquan Li @Guluisacat Dawn Security Lab of JingDongMickey Jin @patch1t Kandji KandjiCsaba Fitzl @theevilbit KandjiMateen Alinaghi Claudio Bozzato Cisco TalosFrancesco Benvenuto Cisco TalosCsaba Fitzl @theevilbit Offensive SecurityYadhu Krishna M Cyber Security At Suma Soft PvtNarendra Bhati Cyber Security At Suma Soft PvtManager Cyber Security At Suma Soft PvtPune (India) Wojciech Regula SecuRing Dawn Security Lab of JingDongKirin @Pwnrin Joshua Jones Jiwon Park an anonymous researcher Marcio Almeida Tanto SecurityBistrit Dahal Srijan Poudel Jiahui Hu (梅零落) NorthSeaMeng Zhang (鲸落) NorthSeaArsenii Kostromin (0x3c3e) Huang Xilin Ant Group LightMaksymilian Motyl Johan Carlsson (joaxcar) Seunghyun Lee @0x10n KAIST Hacking Lab working with Trend Micro Zero Day InitiativeCVE-2024-4558 Matthew Butler Gary Kwong Andreas Jaegersberger Ro Achterberg Ye Zhang @VAR10CK Baidu SecurityJunsung Lee Trend Micro Zero Day InitiativeGandalf4a Minghao Lin Baidu Security Baidu SecurityMichael DePlante @izobashi Trend Micro Zero Day InitiativeD4m0n Amir Bazine CrowdStrike Counter Adversary OperationsKarsten König CrowdStrike Counter Adversary OperationsCVE-2024-2004 CVE-2024-2379 CVE-2024-2398 CVE-2024-2466 CVE-2023-6277 CVE-2023-52356 Yisumi CVE-2024-23296 Matthew Loewen Yann Gascuel Alter Solutionsw0wbox CrowdStrike Counter Adversary OperationsIES Red Team ByteDanceYeto Abhay Kailasia @abhay_kailasia Lakshmi Narain College of Technology Bhopal India secalert@redhat.com

Affected SoftwareAffected VersionHow to fix
Microsoft Azure Arc Resource Bridge
fix available externally
Microsoft Azure Arc Resource Bridge
debian/openssh
1:8.4p1-5+deb11u3
1:9.2p1-2+deb12u3
1:9.8p1-8
Microsoft Azure Arc Resource Bridge
fix available externally
Apple macOS<14.6
14.6
Microsoft CBL-Mariner
fix available externally
Microsoft CBL-Mariner
fix available externally
redhat/openssh 8.7p1<38
38
F5 BIG-IP Next (LTM)>=20.1.0<=20.2.1
F5 BIG-IP Next Central Manager>=20.1.0<=20.2.1
F5 BIG-IP Next>=1.7.0<=1.9.2
F5 BIG-IP Next>=1.1.0<=1.3.1
Fortinet FortiADC>=7.4.0<=7.4.4
Fortinet FortiADC>=7.2.0<=7.2.6
Fortinet FortiAIOps>=2.0.0<=2.0.1
Fortinet FortiAnalyzer>=7.4.0<=7.4.3
Fortinet FortiAnalyzer>=7.2.0<=7.2.5
Fortinet FortiAnalyzer>=7.0.0<=7.0.12
Fortinet FortiAnalyzer>=6.4.0<=6.4.14
Fortinet FortiAnalyzer=.
Fortinet FortiAuthenticator>=6.6.0<=6.6.1
Fortinet FortiDDoS-F>=5.7.0<=5.7.3
Fortinet FortiDDoS-F>=7.0.0<=7.0.1
Fortinet FortiDeceptor>=5.3.0<=5.3.1
Fortinet FortiDeceptor=.
Fortinet FortiExtender Firmware>=7.4.0<=7.4.5
Fortinet FortiExtender Firmware>=7.2.0<=7.2.5
Fortinet FortiExtender Firmware>=7.0.0<=7.0.5
Fortinet FortiLANCloud>=23
Fortinet FortiLANCloud>=22
Fortinet Fortimail-200d>=7.4.0<=7.4.2
Fortinet Fortimail-200d>=7.2.0<=7.2.6
Fortinet Fortimail-200d>=7.0.0<=7.0.7
Fortinet Fortimail-200d>=6.4.0<=6.4.8
Fortinet FortiManager>=7.4.0<=7.4.3
Fortinet FortiManager>=7.2.0<=7.2.5
Fortinet FortiManager>=7.0.0<=7.0.12
Fortinet FortiManager>=6.4.0<=6.4.14
Fortinet FortiManager Cloud>=7.2.3<=7.2.4
Fortinet FortiManager Cloud=.
Fortinet FortiManager Cloud=.
Fortinet FortiManager Cloud>=7.0.6<=7.0.7
Fortinet FortiNAC=.
Fortinet FortiNAC>=7.2.0<=7.2.6
Fortinet FortiRecorder 400D>=7.2.0<=7.2.1
Fortinet FortiRecorder 400D>=7.0.0<=7.0.4
Fortinet FortiRecorder 400D>=6.4.0<=6.4.5
Fortinet FortiRecorder 400D>=6.0.0<=6.0.12
Fortinet FortiSandbox Firmware>=4.4.0<=4.4.6
Fortinet FortiSandbox Firmware>=4.2.0<=4.2.7
Fortinet FortiSandbox Firmware>=4.0.0<=4.0.5
Fortinet FortiSandbox Firmware>=3.2
Fortinet FortiSwitch>=7.4.0<=7.4.3
Fortinet FortiSwitch>=7.2.0<=7.2.8
Fortinet FortiTester>=7.4.0<=7.4.2
Fortinet FortiTester>=7.3.0<=7.3.2
Fortinet FortiTester>=7.2.0<=7.2.3
Fortinet FortiVoice Enterprise>=7.0.0<=7.0.2
Fortinet FortiVoice Enterprise>=6.4.0<=6.4.9
Fortinet FortiWLC>=8.6.0<=8.6.7
Fortinet FortiWeb=.
Fortinet FortiWeb>=7.4.0<=7.4.4
Fortinet FortiWeb>=7.2.0<=7.2.9
Microsoft Azure Kubernetes Service
fix available externally
Microsoft Azure Kubernetes Service
fix available externally
macOS<12.7.6
12.7.6
OpenSSH<4.4
OpenSSH>=8.6<9.8
OpenSSH=4.4
OpenSSH=8.5-p1
Red Hat OpenShift Container Platform=4.0
Red Hat Enterprise Linux=9.0
Red Hat Enterprise Linux Server EUS=9.4
Red Hat Enterprise Linux=9.0_aarch64
Red Hat Enterprise Linux for ARM64 EUS=9.4_aarch64
Red Hat Enterprise Linux for IBM Z Systems=9.0_s390x
Red Hat Enterprise Linux for IBM Z Systems (s390x)=9.4_s390x
Red Hat Enterprise Linux for Power, little endian=9.0_ppc64le
Red Hat Enterprise Linux for Power, little endian - Extended Update Support=9.4_ppc64le
Red Hat Enterprise Linux Server=9.4
SUSE Linux Enterprise Micro Rancher=6.0
Debian=12.0
Ubuntu=22.04
Ubuntu=22.10
Ubuntu=23.04
Amazon Web Services Linux
NetApp E-Series SANtricity OS Controller>=11.0.0<=11.70.2
NetApp ONTAP Select Deploy
NetApp ONTAP Tools for VMware vSphere=9
FreeBSD Kernel=13.2
FreeBSD Kernel=13.2-p1
FreeBSD Kernel=13.2-p10
FreeBSD Kernel=13.2-p11
FreeBSD Kernel=13.2-p2
FreeBSD Kernel=13.2-p3
FreeBSD Kernel=13.2-p4
FreeBSD Kernel=13.2-p5
FreeBSD Kernel=13.2-p6
FreeBSD Kernel=13.2-p7
FreeBSD Kernel=13.2-p8
FreeBSD Kernel=13.2-p9
FreeBSD Kernel=13.3
FreeBSD Kernel=13.3-p1
FreeBSD Kernel=13.3-p2
FreeBSD Kernel=13.3-p3
FreeBSD Kernel=14.0
FreeBSD Kernel=14.0-beta5
FreeBSD Kernel=14.0-p1
FreeBSD Kernel=14.0-p2
FreeBSD Kernel=14.0-p3
FreeBSD Kernel=14.0-p4
FreeBSD Kernel=14.0-p5
FreeBSD Kernel=14.0-p6
FreeBSD Kernel=14.0-p7
FreeBSD Kernel=14.0-rc3
FreeBSD Kernel=14.0-rc4-p1
FreeBSD Kernel=14.1
FreeBSD Kernel=14.1-p1
NetBSD current<=10.0.0
macOS Ventura<13.6.8
13.6.8

Remedy

Set LoginGraceTime to 0 in /etc/ssh/sshd_config. This makes sshd vulnerable to a denial of service (the exhaustion of all MaxStartups connections), but it makes it safe from this vulnerability.

Remedy

https://lists.mindrot.org/pipermail/openssh-unix-dev/2024-July/041431.html

Remedy

https://news.ycombinator.com/item?id=40843778

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Reference Links

Parent vulnerabilities

(Appears in the following advisories)

Peer vulnerabilities

(Found alongside the following vulnerabilities)

Frequently Asked Questions

  • What is the severity of CVE-2024-6387?

    CVE-2024-6387 is considered a critical vulnerability due to the potential for remote code execution in OpenSSH.

  • How do I fix CVE-2024-6387?

    To mitigate CVE-2024-6387, update OpenSSH to the latest version provided by your vendor.

  • Which OpenSSH versions are affected by CVE-2024-6387?

    CVE-2024-6387 affects various OpenSSH versions, but specifically those versions before the fixed releases should be considered vulnerable.

  • What types of systems are impacted by CVE-2024-6387?

    CVE-2024-6387 impacts systems running vulnerable versions of OpenSSH, including servers and devices using CBL Mariner, Fortinet products, and various Linux distributions.

  • Can CVE-2024-6387 be exploited remotely?

    Yes, CVE-2024-6387 can be exploited by an unauthenticated remote attacker under specific conditions.

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