Understanding Garbage Collection and Coalesce Process Troubleshooting

Summary In most cases, customers have experienced issues with coalescing snapshots after deleting snapshots. At times we do notsee the reclaimed space once a snapshot is deleted. Even with an SR rescan to manually get the Garbage Collection GC to kick-in does not reclaim space. This article...

File System on Control Domain Full on XenServer

There are a variety of errors and symptoms that can be seen when the Control Domain file system becomes full. The errors and symptoms that you see might be different depending on the partition layout of your XenServer host. Possible errors can include the following errors or alerts might appear...

Citrix XenServer Multiple Security Updates (CTX202404)

A number of security vulnerabilities have been identified in Citrix XenServer that may allow a malicious administrator of a guest VM to compromise the host and guest users to crash the host. These vulnerabilities affect all currently supported versions of Citrix XenServer up to and including Citr...

Citrix XenServer Security Update for CVE-2015-5307 and CVE-2015-8104 (CTX202583)

A security vulnerability has been identified in Citrix XenServer that may allow a malicious administrator of an HVM guest VM to crash the host. This vulnerability affects all currently supported versions of Citrix XenServer up to and including Citrix XenServer 6.5 Service Pack 1...

Citrix XenServer Multiple Infinite Loop Guest-to-Host DoS (CTX202583)

The version of Citrix XenServer running on the remote host is affected by multiple denial of service vulnerabilities : - An infinite loop condition exists in the KVM subsystem that is triggered when handling a stream of AC Alignment Check exceptions. A local attacker within a virtualized guest ca...

How to Use IIS to Acquire SSL Certificates for XenServer or Citrix Hypervisor

This article describes how to create a certificate in IIS and transfer it to a XenServer or Citrix Hypervisor server. This article applies to Citrix Hypervisor 8.1 or earlier...

How to Disable SR-IOV on Emulex CNA\HBA on HP Hosts Running XenServer 6.5

To Disable SR-IOV on Emulex CNA\HBA...

Changes in Experimental Support for XenApp and Multiple GPUs

What are Experimental Features? This article covers a product configuration or procedure for which Citrix does not currently offer support. Use of this configuration should only be used in a lab or test environment and not with production deployments. Experimental features are occasionally releas...

Vulnerability in Citrix XenServer Could Result in Information Disclosure (CTX201717)

A vulnerability has been identified in Citrix XenServer which could, if exploited, allow a malicious administrator of an HVM guest VM to obtain meta-data about their own VM. Citrix is presently unaware of any meta-data that might be leaked that would be of value to a malicious guest administrator...

Citrix XenServer QEMU RTL8139 Guest Network Device Information Disclosure (CTX201717)

The version of Citrix XenServer running on the remote host is affected by an information disclosure vulnerability due to improper validation of user-supplied input in the C+ mode offload emulation of the RTL8139 network card device model in QEMU. A remote attacker can exploit this to read process...

Citrix XenServer Security Update for CVE-2015-5154 (CTX201593)

A security vulnerability has been identified in Citrix XenServer that may allow a malicious administrator of an HVM guest VM to compromise the host. This vulnerability affects all currently supported versions of Citrix XenServer up to and including Citrix XenServer 6.5 Service Pack 1...

Citrix XenServer QEMU IDE Buffer Overflow Code Execution (CTX201593)

The version of Citrix XenServer running on the remote host is affected by a heap buffer overflow condition in the IDE subsystem of the bundled QEMU software, which is related to I/O buffer access when handling certain ATAPI commands. An attacker, with sufficient privileges in an HVM guest VM, can...

Citrix XenServer Multiple Security Updates (CTX201145)

A number of security vulnerabilities have been identified in Citrix XenServer that may allow a malicious administrator of a guest VM to crash the host. These vulnerabilities affect all currently supported versions of Citrix XenServer up to and including Citrix XenServer 6.5 Service Pack 1...

Citrix XenServer QEMU FDC Buffer Overflow RCE (CTX201078) (VENOM)

The remote host is running a version of Citrix XenServer that is affected by a flaw in the Floppy Disk Controller FDC in the bundled QEMU software due to an overflow condition in hw/block/fdc.c when handling certain commands. An attacker, with access to an account on the guest operating system wi...

Citrix XenServer Multiple Vulnerabilities (CTX200892)

The version of Citrix XenServer installed on the remote host is affected by multiple vulnerabilities : - A flaw exists in the VGA emulator in QEMU that allows a local guest user to read host memory by setting the display to a high resolution. CVE-2014-3615 - A flaw exists in the setpixelformat...

Citrix XenServer Multiple Security Updates (CTX200892)

A number of security vulnerabilities have been identified in Citrix XenServer. These vulnerabilities could, if exploited, allow a malicious administrator of an HVM guest to compromise the host. SPDX-FileCopyrightText: 2015 Greenbone AG Some text descriptions might be excerpted from a referenced...

Citrix Nitro SDK - Command Injection

Citrix Nitro SDK - Command Injection Abstract Securify discovered a command injection vulnerability in xenhotfix page of the NITRO SDK. The attacker-supplied command is executed with elevated privileges nsroot. This issue can be used to compromise of the entire Citrix SDX appliance and all...

CVE-2015-0235 - Citrix Security Advisory for glibc GHOST Vulnerability

Overview A vulnerability has been recently disclosed in the glibc gethostbyname function. This issue could potentially allow an attacker to inject code into a process that calls the vulnerable function. The issue is known as the GHOST vulnerability and has been assigned the following CVE...

Citrix Hypervisor / XenServer Detection (SSH Login)

SSH login-based detection of Citrix Hypervisor / XenServer. SPDX-FileCopyrightText: 2014 Greenbone AG Some text descriptions might be excerpted from a referenced sources, and are Copyright C by the respective right holders. SPDX-License-Identifier: GPL-2.0-only ifdescription...

Citrix XenServer Shellshock Security Update (CTX200223)

A number of security vulnerabilities have been identified in the bash SPDX-FileCopyrightText: 2014 Greenbone AG Some text descriptions might be excerpted from a referenced sources, and are Copyright C by the respective right holders. SPDX-License-Identifier: GPL-2.0-only CPE =...