Search results for openssh --disable-security-key | Breaking Cybersecurity News | The Hacker News

A 'Serious' security vulnerability has been discovered and fixed in OpenSSH – one of the most widely used open-source implementations of the Secure Shell (SSH) Protocol. The critical vulnerability could be exploited by hackers to force clients to leak their secret private cryptographic keys, potentially exposing users to Man-in-the-Middle (MITM) attacks. What Causes the Flaw to occur? The serious bug was actually the result of a code that enables an experimental " roaming " feature in the OpenSSH versions 5.4 to 7.1 in order to let users resume connections. However, The roaming feature contains two different vulnerabilities: An information sharing flaw ( CVE-2016-0777 ) A less harmless buffer overflow flaw ( CVE-2016-0778 ) The vulnerability does not have any catchy name like some previous OpenSSH flaws. Impact of the Vulnerability This new feature can be exploited by hackers, who could use a malicious OpenSSH server to trick a...

OpenSSH 3.5p1 Remote Root Exploit for FreeBSD OpenSSH 3.5p1 Remote Root Exploit for FreeBSD has been shared by kcope on twitter . The Released note is as given below : OpenSSH 3.5p1 Remote Root Exploit for FreeBSD Discovered and Exploited By Kingcope Year 2011 -- The last two days I have been investigating a vulnerability in OpenSSH affecting at least FreeBSD 4.9 and 4.11. These FreeBSD versions run OpenSSH 3.5p1 in the default install. The sshd banner for 4.11-RELEASE is "SSH-1.99-OpenSSH_3.5p1 FreeBSD-20060930". A working Remote Exploit which spawns a root shell remotely and previous to authentication was developed. The bug can be triggered both through ssh version 1 and ssh version 2 using a modified ssh client. During the investigation of the vulnerability it was found that the bug resides in the source code file "auth2-pam-freebsd.c". https://www.freebsd.org/cgi/cvsweb.cgi/src/crypto/openssh/Attic/auth2-pam-freebsd.c This file does not exist in Fre...

In recent years, several groups of cybersecurity researchers have disclosed dozens of memory side-channel vulnerabilities in modern processors and DRAM s, like Rowhammer , RAMBleed , Spectre, and Meltdown . Have you ever noticed they all had at least one thing in common? That's OpenSSH. As a proof-of-concept, many researchers demonstrated their side-channel attacks against OpenSSH application installed on a targeted computer, where an unprivileged attacker-owned process exploits memory read vulnerabilities to steal secret SSH private keys from the restricted memory regions of the system. That's possible because OpenSSH has an agent that keeps a copy of your SSH key in the memory so that you don't have to type your passphrase every time you want to connect to the same remote server. However, modern operating systems by default store sensitive data, including encryption keys and passwords, in the kernel memory which can not be accessed by user-level privileged p...

The maintainers of OpenSSH have released OpenSSH 9.2 to address a number of security bugs, including a memory safety vulnerability in the OpenSSH server (sshd). Tracked as  CVE-2023-25136 , the shortcoming has been classified as a pre-authentication double free vulnerability that was introduced in version 9.1. "This is not believed to be exploitable, and it occurs in the unprivileged pre-auth process that is subject to chroot(2) and is further sandboxed on most major platforms," OpenSSH disclosed in its  release notes  on February 2, 2023. Credited with  reporting  the flaw to OpenSSH in July 2022 is security researcher Mantas Mikulenas. OpenSSH is the open source implementation of the secure shell ( SSH ) protocol that offers a suite of services for encrypted communications over an unsecured network in a client-server architecture. "The exposure occurs in the chunk of memory freed twice, the 'options.kex_algorithms,'" Saeed Abbasi, manager of vulnera...

A simple but highly critical vulnerability recently disclosed in the most widely used OpenSSH software allows attackers to try thousands of password login attempts per connection in a short period. OpenSSH is the most popular software widely used for secure remote access to Linux-based systems. Generally, the software allows 3 to 6 Password login attempts before closing a connection, but a new vulnerability lets attackers perform thousands of authentication requests remotely . OpenSSH servers with keyboard-interactive authentication enabled , including FreeBSD Linux, can be exploited to carry out the brute force attack on OpenSSH protocol, a security researcher with online alias KingCope explained in a blog post . Exploit for the Vulnerability RELEASED  Hackers could widely exploit the vulnerability because the keyboard-interactive authentication is by default enabled on most of the systems. Researcher has also released a proof-of-concept exploit code, whi...

OpenSSH maintainers have released security updates to contain a critical security flaw that could result in unauthenticated remote code execution with root privileges in glibc-based Linux systems. The vulnerability, codenamed regreSSHion, has been assigned the CVE identifier CVE-2024-6387. It resides in the OpenSSH server component , also known as sshd, which is designed to listen for connections from any of the client applications. "The vulnerability, which is a signal handler race condition in OpenSSH's server (sshd), allows unauthenticated remote code execution (RCE) as root on glibc-based Linux systems," Bharat Jogi, senior director of the threat research unit at Qualys, said in a disclosure published today. "This race condition affects sshd in its default configuration." The cybersecurity firm said it identified no less than 14 million potentially vulnerable OpenSSH server instances exposed to the internet, adding it's a regression of an already pa...

Two security vulnerabilities have been discovered in the OpenSSH secure networking utility suite that, if successfully exploited, could result in an active machine-in-the-middle (MitM) and a denial-of-service (DoS) attack, respectively, under certain conditions. The vulnerabilities, detailed by the Qualys Threat Research Unit (TRU), are listed below - CVE-2025-26465 (CVSS score: 6.8)  - The OpenSSH client contains a logic error between versions 6.8p1 to 9.9p1 (inclusive) that makes it vulnerable to an active MitM attack if the VerifyHostKeyDNS option is enabled, allowing a malicious interloper to impersonate a legitimate server when a client attempts to connect to it (Introduced in December 2014) CVE-2025-26466 (CVSS score: 5.9) - The OpenSSH client and server are vulnerable to a pre-authentication DoS attack between versions 9.5p1 to 9.9p1 (inclusive) that causes memory and CPU consumption (Introduced in August 2023) "If an attacker can perform a man-in-the-middle a...

Details have emerged about a now-patched flaw in OpenSSH that could be potentially exploited to run arbitrary commands remotely on compromised hosts under specific conditions. "This vulnerability allows a remote attacker to potentially execute arbitrary commands on vulnerable OpenSSH's forwarded ssh-agent," Saeed Abbasi, manager of vulnerability research at Qualys,  said  in an analysis last week. The vulnerability is being tracked under the CVE identifier  CVE-2023-38408  (CVSS score: N/A). It impacts all versions of OpenSSH before  9.3p2 . OpenSSH is a popular connectivity tool for remote login with the SSH protocol that's used for encrypting all traffic to eliminate eavesdropping, connection hijacking, and other attacks. Successful exploitation requires the presence of certain libraries on the victim system and that the SSH authentication agent is  forwarded  to an attacker-controlled system. SSH agent is a  background program  that ...

The maintainers of the FreeBSD Project have released security updates to address a high-severity flaw in OpenSSH that attackers could potentially exploit to execute arbitrary code remotely with elevated privileges. The vulnerability, tracked as CVE-2024-7589 , carries a CVSS score of 7.4 out of a maximum of 10.0, indicating high severity. "A signal handler in sshd(8) may call a logging function that is not async-signal-safe," according to an advisory released last week. "The signal handler is invoked when a client does not authenticate within the LoginGraceTime seconds (120 by default). This signal handler executes in the context of the sshd(8)'s privileged code, which is not sandboxed and runs with full root privileges." OpenSSH is an implementation of the secure shell (SSH) protocol suite, providing encrypted and authenticated transport for a variety of services, including remote shell access. CVE-2024-7589 has been described as "another instance...

In late 2013, Security Researchers identified thousands of Linux systems around the world infected with the OpenSSH b ackdoor trojan and  credential stealer  named Linux/Ebury ,  that allows  unauthorized access of an affected computer to the remote attackers. Antivirus Firm ESET's Reseacher team has been tracking and  investigating the operation behind Linux/Ebury and today team  uncovers the details [ Report PDF ] of a massive,  sophisticated and organized  malware campaign called ' Operation Windigo ', infected more than 500,000 computers and 25,000 dedicated servers. ' We discovered an infrastructure used for malicious activities that is all hosted on compromised servers. We were also able to find a link between different malware components such as Linux/Cdorked, Perl/Calfbot and Win32/Glupteba.M and realized they are all operated by the same group. '  ESET reported. Malware used in Operation Windigo: Linu...

Select versions of the OpenSSH secure networking suite are susceptible to a new vulnerability that can trigger remote code execution (RCE). The vulnerability, tracked as CVE-2024-6409 (CVSS score: 7.0), is distinct from CVE-2024-6387 (aka RegreSSHion) and relates to a case of code execution in the privsep child process due to a race condition in signal handling. It only impacts versions 8.7p1 and 8.8p1 shipped with Red Hat Enterprise Linux 9. Security researcher Alexander Peslyak, who goes by the alias Solar Designer, has been credited with discovering and reporting the bug, which was found during a review of CVE-2024-6387 after the latter was disclosed by Qualys earlier this month. "The main difference from CVE-2024-6387 is that the race condition and RCE potential are triggered in the privsep child process, which runs with reduced privileges compared to the parent server process," Peslyak said . "So the immediate impact is lower. However, there may be differenc...

Kernel.org Server Rooted and 448 users credentials compromised The main kernel.org page is currently carrying a notice that the site has suffered a security breach. " Earlier this month, a number of servers in the kernel.org infrastructure were compromised. We discovered this August 28th. While we currently believe that the source code repositories were unaffected, we are in the process of verifying this and taking steps to enhance security across the kernel.org infrastructure. " As the update mentions, there's little to be gained by tampering with the git repositories there anyway. The infection occurred no later than August 12 and wasn't detected for another 17 days. The systems were infected by an off-the-shelf, a self-injecting rootkit known as Phalanx that has attacked sensitive Linux systems before. What happened? Intruders gained root access on the server Hera. We believe they may have gained this access via a compromised user credential; how they man...

Security researchers from Ruhr University Bochum have discovered a vulnerability in the Secure Shell ( SSH ) cryptographic network protocol that could allow an attacker to downgrade the connection's security by breaking the integrity of the secure channel. Called  Terrapin  ( CVE-2023-48795 , CVSS score: 5.9), the exploit has been described as the "first ever practically exploitable prefix truncation attack." "By carefully adjusting the sequence numbers during the handshake, an attacker can remove an arbitrary amount of messages sent by the client or server at the beginning of the secure channel without the client or server noticing it," researchers Fabian Bäumer, Marcus Brinkmann, and Jörg Schwenk  said . SSH is a  method  for securely sending commands to a computer over an unsecured network. It relies on cryptography to authenticate and encrypt connections between devices. This is accomplished by means of a handshake in which a client and server agree up...

Until now Unix and Linux system administrators have to download a third-party SSH client software like Putty on their Windows machines to securely manage their machines and servers remotely through Secure Shell protocol or Shell Session (better known as SSH ). This might have always been an awkward feature of Windows platform, as it lacks both – a native SSH client software for connecting to Linux machines, and an SSH server to support inbound connections from Linux machines. But… Believe it or not: You don't need to deal with any third-party SSH client now, as Microsoft is working on supporting OpenSSH. Yes, Microsoft has finally decided to bring OpenSSH client and server to Windows. The PowerShell team at Microsoft has announced that the company is going to support and contribute to OpenSSH community in an effort to deliver better SSH support in the PowerShell and Windows SSH software solutions. So, the upcoming version of Windows PowerShell – the co...

Internet-facing Linux systems and Internet of Things (IoT) devices are being targeted as part of a new campaign designed to illicitly mine cryptocurrency. "The threat actors behind the attack use a backdoor that deploys a wide array of tools and components such as rootkits and an IRC bot to steal device resources for mining operations," Microsoft threat intelligence researcher Rotem Sde-Or  said . "The backdoor also installs a patched version of OpenSSH on affected devices, allowing threat actors to hijack SSH credentials, move laterally within the network, and conceal malicious SSH connections." To pull off the scheme, misconfigured Linux hosts are brute-forced to gain initial access, following which the threat actors move to disable shell history and fetch a trojanized version of OpenSSH from a remote server. The rogue OpenSSH package is configured to install and launch the backdoor, a shell script that allows the attackers to distribute additional payloads a...

A set of 36-year-old vulnerabilities has been uncovered in the Secure Copy Protocol (SCP) implementation of many client applications that can be exploited by malicious servers to overwrite arbitrary files in the SCP client target directory unauthorizedly. Session Control Protocol (SCP), also known as secure copy, is a network protocol that allows users to securely transfer files between a local host and a remote host using RCP (Remote Copy Protocol) and SSH protocol. In other terms, SCP, which dates back to 1983, is a secure version of RCP that uses authentication and encryption of SSH protocol to transfer files between a server and a client. Discovered by Harry Sintonen, one of F-Secure's Senior Security Consultants, the vulnerabilities exist due to poor validations performed by the SCP clients, which can be abused by malicious servers or man-in-the-middle (MiTM) attackers to drop or overwrite arbitrary files on the client's system. "Many scp clients fail to ver...

Threat actors are leveraging weaponized attachments distributed via phishing emails to deliver malware likely targeting the defense sector in Russia and Belarus. According to multiple reports from Cyble and Seqrite Labs , the campaign is designed to deploy a persistent backdoor on compromised hosts that uses OpenSSH in conjunction with a customized Tor hidden service that employs obfs4 for traffic obfuscation. The activity has been codenamed Operation SkyCloak by Seqrite, stating the phishing emails utilize lures related to military documents to convince recipients into opening a ZIP file containing a hidden folder with a second archive file, along with a Windows shortcut (LNK) file, which, when opened, triggers the multi-step infection chain. "They trigger PowerShell commands which act as the initial dropper stage where another archive file besides the LNK is used to set up the entire chain," security researchers Sathwik Ram Prakki and Kartikkumar Jivani said, adding...

PuTTY v.0.61  New Version   released  After 4 years After four Years, Putty's New version finally Released today.Here are the PuTTY files themselves: PuTTY (the Telnet and SSH client itself) PSCP (an SCP client, i.e. command-line secure file copy) PSFTP (an SFTP client, i.e. general file transfer sessions much like FTP) PuTTYtel (a Telnet-only client) Plink (a command-line interface to the PuTTY back ends) Pageant (an SSH authentication agent for PuTTY, PSCP, PSFTP, and Plink) PuTTYgen (an RSA and DSA key generation utility). These features are new in beta 0.61 Kerberos/GSSAPI authentication in SSH-2. Local X11 authorisation support on Windows. (Unix already had it, of course.) Support for non-fixed-width fonts on Windows. GTK 2 support on Unix. Specifying the logical host name independently of the physical network address to connect to. Crypto and flow control optimisations. Support for the zlib@openssh.com SSH-2 compression method. Support for new Wind...

Cybersecurity today is less about single attacks and more about chains of small weaknesses that connect into big risks. One overlooked update, one misused account, or one hidden tool in the wrong hands can be enough to open the door. The news this week shows how attackers are mixing methods—combining stolen access, unpatched software, and clever tricks to move from small entry points to large consequences.  For defenders, the lesson is clear: the real danger often comes not from one major flaw, but from how different small flaws interact together. ⚡ Threat of the Week WhatsApp Patches Actively Exploited Flaw — WhatsApp addressed a security vulnerability in its messaging apps for Apple iOS and macOS that it said may have been exploited in the wild in conjunction with a recently disclosed Apple flaw in targeted zero-day attacks. The vulnerability, CVE-2025-55177 relates to a case of insufficient authorization of linked device synchronization messages. The Meta-owned company ...