ID CVE-2011-0011
Summary qemu-kvm before 0.11.0 disables VNC authentication when the password is cleared, which allows remote attackers to bypass authentication and establish VNC sessions.
References
Vulnerable Configurations
  • QEMU 0.11.0 release candidate 2
    cpe:2.3:a:qemu:qemu:0.11.0:rc2
  • QEMU 0.11.0 release candidate 1
    cpe:2.3:a:qemu:qemu:0.11.0:rc1
  • QEMU 0.11.0-rc0
    cpe:2.3:a:qemu:qemu:0.11.0:rc0
  • QEMU 0.10.6
    cpe:2.3:a:qemu:qemu:0.10.6
  • QEMU 0.10.5
    cpe:2.3:a:qemu:qemu:0.10.5
  • QEMU 0.10.4
    cpe:2.3:a:qemu:qemu:0.10.4
  • QEMU 0.10.3
    cpe:2.3:a:qemu:qemu:0.10.3
  • QEMU 0.10.2
    cpe:2.3:a:qemu:qemu:0.10.2
  • QEMU 0.10.1
    cpe:2.3:a:qemu:qemu:0.10.1
  • QEMU 0.10.0
    cpe:2.3:a:qemu:qemu:0.10.0
  • QEMU 0.1.6
    cpe:2.3:a:qemu:qemu:0.1.6
  • QEMU 0.1.5
    cpe:2.3:a:qemu:qemu:0.1.5
  • QEMU 0.1.4
    cpe:2.3:a:qemu:qemu:0.1.4
  • QEMU 0.1.3
    cpe:2.3:a:qemu:qemu:0.1.3
  • QEMU 0.1.2
    cpe:2.3:a:qemu:qemu:0.1.2
  • QEMU 0.1.1
    cpe:2.3:a:qemu:qemu:0.1.1
  • QEMU 0.1
    cpe:2.3:a:qemu:qemu:0.1
CVSS
Base: 4.3 (as of 21-06-2012 - 15:23)
Impact:
Exploitability:
CWE CWE-287
CAPEC
  • Authentication Abuse
    An attacker obtains unauthorized access to an application, service or device either through knowledge of the inherent weaknesses of an authentication mechanism, or by exploiting a flaw in the authentication scheme's implementation. In such an attack an authentication mechanism is functioning but a carefully controlled sequence of events causes the mechanism to grant access to the attacker. This attack may exploit assumptions made by the target's authentication procedures, such as assumptions regarding trust relationships or assumptions regarding the generation of secret values. This attack differs from Authentication Bypass attacks in that Authentication Abuse allows the attacker to be certified as a valid user through illegitimate means, while Authentication Bypass allows the user to access protected material without ever being certified as an authenticated user. This attack does not rely on prior sessions established by successfully authenticating users, as relied upon for the "Exploitation of Session Variables, Resource IDs and other Trusted Credentials" attack patterns.
  • Exploiting Trust in Client (aka Make the Client Invisible)
    An attack of this type exploits a programs' vulnerabilities in client/server communication channel authentication and data integrity. It leverages the implicit trust a server places in the client, or more importantly, that which the server believes is the client. An attacker executes this type of attack by placing themselves in the communication channel between client and server such that communication directly to the server is possible where the server believes it is communicating only with a valid client. There are numerous variations of this type of attack.
  • Utilizing REST's Trust in the System Resource to Register Man in the Middle
    This attack utilizes a REST(REpresentational State Transfer)-style applications' trust in the system resources and environment to place man in the middle once SSL is terminated. Rest applications premise is that they leverage existing infrastructure to deliver web services functionality. An example of this is a Rest application that uses HTTP Get methods and receives a HTTP response with an XML document. These Rest style web services are deployed on existing infrastructure such as Apache and IIS web servers with no SOAP stack required. Unfortunately from a security standpoint, there frequently is no interoperable identity security mechanism deployed, so Rest developers often fall back to SSL to deliver security. In large data centers, SSL is typically terminated at the edge of the network - at the firewall, load balancer, or router. Once the SSL is terminated the HTTP request is in the clear (unless developers have hashed or encrypted the values, but this is rare). The attacker can utilize a sniffer such as Wireshark to snapshot the credentials, such as username and password that are passed in the clear once SSL is terminated. Once the attacker gathers these credentials, they can submit requests to the web service provider just as authorized user do. There is not typically an authentication on the client side, beyond what is passed in the request itself so once this is compromised, then this is generally sufficient to compromise the service's authentication scheme.
  • Man in the Middle Attack
    This type of attack targets the communication between two components (typically client and server). The attacker places himself in the communication channel between the two components. Whenever one component attempts to communicate with the other (data flow, authentication challenges, etc.), the data first goes to the attacker, who has the opportunity to observe or alter it, and it is then passed on to the other component as if it was never intercepted. This interposition is transparent leaving the two compromised components unaware of the potential corruption or leakage of their communications. The potential for Man-in-the-Middle attacks yields an implicit lack of trust in communication or identify between two components.
Access
VectorComplexityAuthentication
ADJACENT_NETWORK HIGH NONE
Impact
ConfidentialityIntegrityAvailability
PARTIAL PARTIAL PARTIAL
nessus via4
  • NASL family Ubuntu Local Security Checks
    NASL id UBUNTU_USN-1063-1.NASL
    description Neil Wilson discovered that if VNC passwords were blank in QEMU configurations, access to VNC sessions was allowed without a password instead of being disabled. A remote attacker could connect to running VNC sessions of QEMU and directly control the system. By default, QEMU does not start VNC sessions. Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
    last seen 2019-02-21
    modified 2018-12-01
    plugin id 51986
    published 2011-02-15
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=51986
    title Ubuntu 9.10 / 10.04 LTS / 10.10 : qemu-kvm vulnerability (USN-1063-1)
  • NASL family Debian Local Security Checks
    NASL id DEBIAN_DSA-2230.NASL
    description Two vulnerabilities have been discovered in KVM, a solution for full virtualization on x86 hardware : - CVE-2011-0011 Setting the VNC password to an empty string silently disabled all authentication. - CVE-2011-1750 The virtio-blk driver performed insufficient validation of read/write I/O from the guest instance, which could lead to denial of service or privilege escalation. The oldstable distribution (lenny) is not affected by this problem.
    last seen 2019-02-21
    modified 2018-11-10
    plugin id 53605
    published 2011-05-02
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=53605
    title Debian DSA-2230-1 : qemu-kvm - several vulnerabilities
  • NASL family Scientific Linux Local Security Checks
    NASL id SL_20110310_QEMU_KVM_ON_SL6_X.NASL
    description A flaw was found in the way the VNC 'password' option was handled. Clearingaa password disabled VNC authentication, allowing a remote user able to connect to the virtual machines' VNC ports to open a VNC session without authentication. (CVE-2011-0011) After installing this update, shut down all running virtual machines. Once all virtual machines have shut down, start them again for this update to take effect.
    last seen 2019-02-21
    modified 2018-12-31
    plugin id 60989
    published 2012-08-01
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=60989
    title Scientific Linux Security Update : qemu-kvm on SL6.x x86_64
  • NASL family Oracle Linux Local Security Checks
    NASL id ORACLELINUX_ELSA-2011-0345.NASL
    description From Red Hat Security Advisory 2011:0345 : Updated qemu-kvm packages that fix one security issue are now available for Red Hat Enterprise Linux 6. The Red Hat Security Response Team has rated this update as having moderate security impact. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available from the CVE link in the References section. KVM (Kernel-based Virtual Machine) is a full virtualization solution for Linux on AMD64 and Intel 64 systems. qemu-kvm is the user-space component for running virtual machines using KVM. Virtual Network Computing (VNC) is a remote display system. A flaw was found in the way the VNC 'password' option was handled. Clearing a password disabled VNC authentication, allowing a remote user able to connect to the virtual machines' VNC ports to open a VNC session without authentication. (CVE-2011-0011) All users of qemu-kvm should upgrade to these updated packages, which contain a backported patch to resolve this issue. After installing this update, shut down all running virtual machines. Once all virtual machines have shut down, start them again for this update to take effect.
    last seen 2019-02-21
    modified 2018-07-18
    plugin id 68227
    published 2013-07-12
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=68227
    title Oracle Linux 6 : qemu-kvm (ELSA-2011-0345)
  • NASL family Red Hat Local Security Checks
    NASL id REDHAT-RHSA-2011-0345.NASL
    description Updated qemu-kvm packages that fix one security issue are now available for Red Hat Enterprise Linux 6. The Red Hat Security Response Team has rated this update as having moderate security impact. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available from the CVE link in the References section. KVM (Kernel-based Virtual Machine) is a full virtualization solution for Linux on AMD64 and Intel 64 systems. qemu-kvm is the user-space component for running virtual machines using KVM. Virtual Network Computing (VNC) is a remote display system. A flaw was found in the way the VNC 'password' option was handled. Clearing a password disabled VNC authentication, allowing a remote user able to connect to the virtual machines' VNC ports to open a VNC session without authentication. (CVE-2011-0011) All users of qemu-kvm should upgrade to these updated packages, which contain a backported patch to resolve this issue. After installing this update, shut down all running virtual machines. Once all virtual machines have shut down, start them again for this update to take effect.
    last seen 2019-02-21
    modified 2018-11-26
    plugin id 63974
    published 2013-01-24
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=63974
    title RHEL 6 : qemu-kvm (RHSA-2011:0345)
redhat via4
advisories
bugzilla
id 668589
title CVE-2011-0011 qemu-kvm: Setting VNC password to empty string silently disables all authentication
oval
AND
  • OR
    • comment Red Hat Enterprise Linux 6 Client is installed
      oval oval:com.redhat.rhba:tst:20111656001
    • comment Red Hat Enterprise Linux 6 Server is installed
      oval oval:com.redhat.rhba:tst:20111656002
    • comment Red Hat Enterprise Linux 6 Workstation is installed
      oval oval:com.redhat.rhba:tst:20111656003
    • comment Red Hat Enterprise Linux 6 ComputeNode is installed
      oval oval:com.redhat.rhba:tst:20111656004
  • OR
    • AND
      • comment qemu-img is earlier than 2:0.12.1.2-2.113.el6_0.8
        oval oval:com.redhat.rhsa:tst:20110345007
      • comment qemu-img is signed with Red Hat redhatrelease2 key
        oval oval:com.redhat.rhsa:tst:20110345008
    • AND
      • comment qemu-kvm is earlier than 2:0.12.1.2-2.113.el6_0.8
        oval oval:com.redhat.rhsa:tst:20110345005
      • comment qemu-kvm is signed with Red Hat redhatrelease2 key
        oval oval:com.redhat.rhsa:tst:20110345006
    • AND
      • comment qemu-kvm-tools is earlier than 2:0.12.1.2-2.113.el6_0.8
        oval oval:com.redhat.rhsa:tst:20110345009
      • comment qemu-kvm-tools is signed with Red Hat redhatrelease2 key
        oval oval:com.redhat.rhsa:tst:20110345010
rhsa
id RHSA-2011:0345
released 2011-03-10
severity Moderate
title RHSA-2011:0345: qemu-kvm security update (Moderate)
rpms
  • qemu-img-2:0.12.1.2-2.113.el6_0.8
  • qemu-kvm-2:0.12.1.2-2.113.el6_0.8
  • qemu-kvm-tools-2:0.12.1.2-2.113.el6_0.8
refmap via4
misc https://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/697197
mlist
  • [oss-security] 20110110 CVE request: qemu-kvm: Setting VNC password to empty string silently disables all authentication
  • [oss-security] 20110110 Re: CVE request: qemu-kvm: Setting VNC password to empty string silently disables all authentication
  • [oss-security] 20110112 Re: CVE request: qemu-kvm: Setting VNC password to empty string silently disables all authentication
osvdb 70992
secunia
  • 42830
  • 43272
  • 43733
  • 44393
ubuntu USN-1063-1
xf qemu-vnc-security-bypass(65215)
Last major update 21-06-2012 - 00:00
Published 21-06-2012 - 11:55
Last modified 16-08-2017 - 21:33
Back to Top