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The Hacker News - Cybersecurity News and Analysis: ssh exploit

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

Libssh Releases Update to Patch 9 New Security Vulnerabilities

Libssh Releases Update to Patch 9 New Security Vulnerabilities
March 19, 2019Wang Wei
Libssh2, a popular open source client-side C library implementing the SSHv2 protocol, has released the latest version of its software to patch a total of nine security vulnerabilities. The Libssh2 library is available for all major distributors of the Linux operating systems, including Ubuntu, Red Hat, Debian, and also comes bundled within some distributions and software as a default library. According to an  advisory published Monday, all the below listed vulnerabilities that were patched with the release of libssh2 version 1.8.1 lead to memory corruption issues which could result in arbitrary code execution on a client system in certain circumstances. Here's the list of security vulnerabilities patched in Libssh: 1. CVE-2019-3855: Possible integer overflow in transport read that could lead to an out-of-bounds write. A malicious server, or a remote attacker who compromises an SSH server, could send a specially crafted packet which could result in executing malicious

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

Remote 0day Exploit for Tectia SSH Server released

Remote 0day Exploit for Tectia SSH Server released
December 02, 2012Mohit Kumar
Hacker @kingcope discovered critical vulnerability in Tectia SSH Server. Exploit working on SSH-2.0-6.1.9.95 SSH Tectia Server (Latest available version from www.tectia.com) that allow attacker to bypass Authentication remotely. Description :  An attacker in the possession of a valid username of an SSH Tectia installation running on UNIX (verified on AIX/Linux) can login without a password. The bug is in the "SSH USERAUTH CHANGE REQUEST" routines which are there to allow a user to change their password. A bug in the code allows an attacker to login without a password by forcing a password change request prior to authentication. Download Exploit Code : Click Here A default installation on Linux (version 6.1.9.95 of Tectia) is vulnerable to the attack. Eric Romang posted a Demo video on Youtube, hope you will like it :) Command Source : https://goo.gl/BHqWd
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