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The Hacker News - Cybersecurity News and Analysis: OpenSSH

OpenSSH now supports FIDO U2F security keys for 2-factor authentication

OpenSSH now supports FIDO U2F security keys for 2-factor authentication
February 17, 2020Swati Khandelwal
Here's excellent news for sysadmins. You can now use a physical security key as hardware-based two-factor authentication to securely log into a remote system via SSH protocol. OpenSSH, one of the most widely used open-source implementations of the Secure Shell (SSH) Protocol, yesterday announced the 8.2 version of the software that primarily includes two new significant security enhancements. First, OpenSSH 8.2 added support for FIDO/U2F hardware authenticators , and the second, it has deprecated SSH-RSA public key signature algorithm and planned to disable it by default in the future versions of the software. FIDO (Fast Identity Online) protocol based hardware security devices are stronger and fool-proof mechanisms for authentication because it enables public-key cryptography to protect against advanced malware, phishing, and man-in-the-middle attacks. "In OpenSSH, FIDO devices are supported by new public key types' ecdsa-sk' and 'ed25519-sk', along

OpenSSH Now Encrypts Secret Keys in Memory Against Side-Channel Attacks

OpenSSH Now Encrypts Secret Keys in Memory Against Side-Channel Attacks
June 22, 2019Mohit Kumar
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

36-Year-Old SCP Clients' Implementation Flaws Discovered

36-Year-Old SCP Clients' Implementation Flaws Discovered
January 15, 2019Mohit Kumar
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

LibSSH Flaw Allows Hackers to Take Over Servers Without Password

LibSSH Flaw Allows Hackers to Take Over Servers Without Password
October 17, 2018Mohit Kumar
A four-year-old severe vulnerability has been discovered in the Secure Shell (SSH) implementation library known as Libssh that could allow anyone to completely bypass authentication and gain unfettered administrative control over a vulnerable server without requiring a password. The security vulnerability, tracked as CVE-2018-10933 , is an authentication-bypass issue that was introduced in Libssh version 0.6 released earlier 2014, leaving thousands of enterprise servers open to hackers for the last four years. But before you get frightened, you should know that neither the widely used OpenSSH nor Github's implementation of libssh was affected by the vulnerability. The vulnerability resides due to a coding error in Libssh and is "ridiculously simple" to exploit. According to a security advisory published Tuesday, all an attacker needs to do is sending an "SSH2_MSG_USERAUTH_SUCCESS" message to a server with an SSH connection enabled when it expects an &

12-Year-Old SSH Bug Exposes More than 2 Million IoT Devices

12-Year-Old SSH Bug Exposes More than 2 Million IoT Devices
October 14, 2016Mohit Kumar
Are your internet-connected devices spying on you? Perhaps. We already know that the Internet of Thing (IoT) devices are so badly insecure that hackers are adding them to their botnet network for launching Distributed Denial of Service (DDoS) attacks against target services. But, these connected devices are not just limited to conduct DDoS attacks ; they have far more potential to harm you. New research [ PDF ] published by the content delivery network provider Akamai Technologies shows how unknown threat actors are using a 12-year-old vulnerability in OpenSSH to secretly gain control of millions of connected devices. The hackers then turn, what researchers call, these " Internet of Unpatchable Things " into proxies for malicious traffic to attack internet-based targets and 'internet-facing' services, along with the internal networks that host them. Unlike recent attacks via Mirai botnet , the new targeted attack, dubbed SSHowDowN Proxy , specifically ma

Critical OpenSSH Flaw Leaks Private Crypto Keys to Hackers

Critical OpenSSH Flaw Leaks Private Crypto Keys to Hackers
January 15, 2016Swati Khandelwal
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

Bug in OpenSSH Opens Linux Machines to Password Cracking Attack

Bug in OpenSSH Opens Linux Machines to Password Cracking Attack
July 23, 2015Swati Khandelwal
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, which i

Web-based DropCam Surveillance Systems Vulnerable to Hackers

Web-based DropCam Surveillance Systems Vulnerable to Hackers
July 15, 2014Wang Wei
The popular home surveillance webcam service DropCam that keep an eye on your house when you aren't there, can be used as a weapon against you by the cybercriminals, claimed a pair of researchers. San Francisco-based DropCam, last month announced it would be acquired by Google's Nest for $555 million in cash, makes home-monitoring cameras for the past five years, which allow users to keep track of what's going on inside their homes using a small surveillance camera. Two researchers named Patrick Wardle and Colby Moore of Synack who discovered the weakness in the Wi-Fi enabled video monitoring system, which they will demonstrate at the DEFCON 22 Hacker Conference in Las Vegas next month. This WiFi-enabled security camera, that comes for $149 or $199, depending on video quality, requires little-to-no-effort to maintain. You plug it in, get it up on your WiFi, and all is set. If you want to check in on your cameras remotely, it cost you nothing, and if you want DropCam

Operation Windigo: Linux malware campaign that infected 500,000 Computers Worldwide

Operation Windigo: Linux malware campaign that infected 500,000 Computers Worldwide
March 18, 2014Mohit Kumar
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: Linux/Ebury –  an OpenSSH backdoor use

New Mac malware opens secure connection for a remote hacker

New Mac malware opens secure connection for a remote hacker
February 20, 2013Mohit Kumar
A new malware threat for the Mac has been discovered that attempting to set up a secure connection for a remote hacker to connect through and grab private information. Dubbed " Pintsized " that uses a modified version of OpenSSH to potentially set up a remote connection into Mac accounts. This backdoor Trojan can be used to conduct distributed denial of service (DDoS) attacks, or it can be used to install additional Trojans or other forms of malicious software. Since the connection between the hacker and the machine is encrypted, it becomes very hard for the Trojan to be detected or traced. The threat has the potential to become serious, as it uses an exploit in OS X to bypass Gatekeeper and establish a reverse shell that creates a secure connection.  Trojan stays hidden by disguising itself as a file that is used for networked printers in Mac OS X. The location of the malware has been traced to this particular directory. This tactic conceals the Trojan and makes a moni
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