This is a serious violation of the security barrier enforced by the hypervisor and poses a particular threat to multi-tenant data centers where the customers ' virtualized servers share the same underlying hardware . The open-source Xen hypervisor is used by cloud computing providers and virtual private server hosting companies , as well as by security-oriented operating systems like Qubes OS . The new vulnerability affects Vulnerability-related.DiscoverVulnerability Xen 4.8.x , 4.7.x , 4.6.x , 4.5.x , and 4.4.x and has existed in the Xen code base for over four years . It was unintentionally introduced Vulnerability-related.DiscoverVulnerability in December 2012 as part of a fix for a different issue . The Xen project released Vulnerability-related.PatchVulnerability a patch Tuesday that can be applied manually to vulnerable deployments . The good news is that the vulnerability can only be exploited Vulnerability-related.DiscoverVulnerability from 64-bit paravirtualized guest operating systems . Xen supports two types of virtual machines : Hardware Virtual Machines ( HVMs ) , which use hardware-assisted virtualization , and paravirtualized ( PV ) VMs that use software-based virtualization . Based on whether they use PV VMs , Xen users might be affected or not . For example , Amazon Web Services said in Vulnerability-related.DiscoverVulnerability an advisory that its customers ' data and instances were not affected Vulnerability-related.DiscoverVulnerability by this vulnerability and no customer action is required . Meanwhile , virtual private server provider Linode had to reboot some of its legacy Xen servers in order to apply Vulnerability-related.PatchVulnerability the fix . Qubes OS , an operating system that uses Xen to isolate applications inside virtual machines , also put out an advisory warning Vulnerability-related.DiscoverVulnerability that an attacker who exploits another vulnerability , for example inside a browser , can exploit Vulnerability-related.DiscoverVulnerability this Xen issue to compromise the whole Qubes system . The Qubes developers have released Vulnerability-related.PatchVulnerability a patched Xen package for Qubes 3.1 & 3.2 and reiterated their intention to stop using paravirtualization altogether in the upcoming Qubes 4.0 . Vulnerabilities that allow breaking the isolation layer of virtual machines can be very valuable for attackers .

The industrial company on Tuesday released Vulnerability-related.PatchVulnerability mitigations for eight vulnerabilities overall . Siemens AG on Tuesday issued Vulnerability-related.PatchVulnerability a slew of fixes addressing Vulnerability-related.PatchVulnerability eight vulnerabilities spanning its industrial product lines . The most serious of the patched flaws include a cross-site scripting vulnerability in Siemens ’ SCALANCE firewall product . The flaw could allow an attacker to gain unauthorized access Attack.Databreach to industrial networks and ultimately put operations and production at risk . The SCALANCE S firewall is used to protect secure industrial networks from untrusted network traffic , and allows filtering incoming and outgoing network connections in different ways . Siemens S602 , S612 , S623 , S627-2M SCALANCE devices with software versions prior to V4.0.1.1 are impacted Vulnerability-related.DiscoverVulnerability . Researchers with Applied Risk , who discovered Vulnerability-related.DiscoverVulnerability the flaw , said Vulnerability-related.DiscoverVulnerability that vulnerability exists in Vulnerability-related.DiscoverVulnerability the web server of the firewall software . An attacker can carry out the attack by crafting Attack.Phishing a malicious link and tricking Attack.Phishing an administrator – who is logged into the web server – to click that link . Once an admin does so , the attacker can execute commands on the web server , on the administrator ’ s behalf . “ The integrated web server allows a cross-site scripting attack if an administrator is misled Attack.Phishing into accessing a malicious link , ” Applied Risk researcher Nelson Berg said in Vulnerability-related.DiscoverVulnerability an analysis Vulnerability-related.DiscoverVulnerability of the flaw . “ Successful exploitation may lead to the ability to bypass critical security measures provided by the firewall. ” Exploitation of this vulnerability could ultimately enable threat actors to bypass critical security functions provided by the firewall , potentially providing access to industrial networks and putting operations and production at risk . The vulnerability , CVE-2018-16555 , has a CVSS score which Applied Risk researcher calculates Vulnerability-related.DiscoverVulnerability to be 8.2 ( or high severity ) . That said , researchers said Vulnerability-related.DiscoverVulnerability a successful exploit is not completely seamless and takes some time and effort to carry out – for an attacker to exploit the flaw , user interaction is required and the administrator must be logged into the web interface . Researchers said Vulnerability-related.DiscoverVulnerability that no exploit of the vulnerability has been discovered Vulnerability-related.DiscoverVulnerability thus far . Siemens addressed Vulnerability-related.PatchVulnerability the reported vulnerability by releasing Vulnerability-related.PatchVulnerability a software update ( V4.0.1.1 ) and also advised customers to “ only access links from trusted sources in the browser you use to access the SCALANCE S administration website. ” The industrial company also released Vulnerability-related.PatchVulnerability an array of fixes for other vulnerabilities on Tuesday . Overall , eight advisories were released by the US CERT . Another serious vulnerability ( CVE-2018-16556 ) addressed Vulnerability-related.PatchVulnerability was an improper input validation flaw in certain Siemens S7-400 CPUs . Successful exploitation of these vulnerabilities could crash the device being accessed which may require a manual reboot or firmware re-image to bring the system back to normal operation , according to the advisory . “ Specially crafted packets sent to Port 102/TCP via Ethernet interface , via PROFIBUS , or via multi-point interfaces ( MPI ) could cause the affected devices to go into defect mode . Manual reboot is required to resume normal operation , ” according to US Cert . An improper access control vulnerability that is exploitable Vulnerability-related.DiscoverVulnerability remotely in Siemens IEC 61850 system configurator , DIGSI 5 , DIGSI 4 , SICAM PAS/PQS , SICAM PQ Analyzer , and SICAM SCC , was also mitigated Vulnerability-related.PatchVulnerability . The vulnerability , CVE-2018-4858 , has a CVSS of 4.2 and exists in Vulnerability-related.DiscoverVulnerability a service of the affected products listening on all of the host ’ s network interfaces on either Port 4884/TCP , Port 5885/TCP , or Port 5886/TCP . The service could allow an attacker to either exfiltrate Attack.Databreach limited data from the system or execute code with Microsoft Windows user permissions . Also mitigated Vulnerability-related.PatchVulnerability were an improper authentication vulnerability ( CVE-2018-13804 ) in SIMATIC IT Production Suite and a code injection vulnerability ( CVE-2018-13814 ) in SIMATIC Panels and SIMATIC WinCC that could allow an attacker with network access to the web server to perform a HTTP header injection attack .