ID CVE-2011-2527
Summary The change_process_uid function in os-posix.c in Qemu 0.14.0 and earlier does not properly drop group privileges when the -runas option is used, which allows local guest users to access restricted files on the host.
References
Vulnerable Configurations
  • QEMU 0.13.0 release candidate 1
    cpe:2.3:a:qemu:qemu:0.13.0:rc1
  • QEMU 0.13.0 release candidate 0
    cpe:2.3:a:qemu:qemu:0.13.0:rc0
  • QEMU 0.13.0
    cpe:2.3:a:qemu:qemu:0.13.0
  • QEMU 0.14.0
    cpe:2.3:a:qemu:qemu:0.14.0
  • QEMU 0.12.0 release candidate 1
    cpe:2.3:a:qemu:qemu:0.12.0:rc1
  • QEMU 0.12.5
    cpe:2.3:a:qemu:qemu:0.12.5
  • QEMU 0.12.4
    cpe:2.3:a:qemu:qemu:0.12.4
  • QEMU 0.12.0
    cpe:2.3:a:qemu:qemu:0.12.0
  • QEMU 0.12.0 release candidate 2
    cpe:2.3:a:qemu:qemu:0.12.0:rc2
  • QEMU 0.12.1
    cpe:2.3:a:qemu:qemu:0.12.1
  • QEMU 0.12.3
    cpe:2.3:a:qemu:qemu:0.12.3
  • QEMU 0.12.2
    cpe:2.3:a:qemu:qemu:0.12.2
  • QEMU 0.11.1
    cpe:2.3:a:qemu:qemu:0.11.1
  • 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 0.11.0
    cpe:2.3:a:qemu:qemu:0.11.0
  • 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 0.10.6
    cpe:2.3:a:qemu:qemu:0.10.6
  • 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 0.10.3
    cpe:2.3:a:qemu:qemu:0.10.3
  • QEMU 0.10.2
    cpe:2.3:a:qemu:qemu:0.10.2
  • QEMU 0.9.1
    cpe:2.3:a:qemu:qemu:0.9.1
  • QEMU 0.9.1-5
    cpe:2.3:a:qemu:qemu:0.9.1-5
  • QEMU 0.9.0
    cpe:2.3:a:qemu:qemu:0.9.0
  • QEMU 0.8.0
    cpe:2.3:a:qemu:qemu:0.8.0
  • QEMU 0.8.1
    cpe:2.3:a:qemu:qemu:0.8.1
  • QEMU 0.8.2
    cpe:2.3:a:qemu:qemu:0.8.2
  • QEMU 0.7.2
    cpe:2.3:a:qemu:qemu:0.7.2
  • QEMU 0.7.1
    cpe:2.3:a:qemu:qemu:0.7.1
  • QEMU 0.7.0
    cpe:2.3:a:qemu:qemu:0.7.0
  • QEMU 0.6.1
    cpe:2.3:a:qemu:qemu:0.6.1
  • QEMU 0.6.0
    cpe:2.3:a:qemu:qemu:0.6.0
  • QEMU 0.4.1
    cpe:2.3:a:qemu:qemu:0.4.1
  • QEMU 0.4
    cpe:2.3:a:qemu:qemu:0.4
  • QEMU 0.4.3
    cpe:2.3:a:qemu:qemu:0.4.3
  • QEMU 0.4.2
    cpe:2.3:a:qemu:qemu:0.4.2
  • QEMU 0.3
    cpe:2.3:a:qemu:qemu:0.3
  • QEMU 0.2
    cpe:2.3:a:qemu:qemu:0.2
  • QEMU 0.14.0 release candidate 0
    cpe:2.3:a:qemu:qemu:0.14.0:rc0
  • QEMU 0.14.0 release candidate 2
    cpe:2.3:a:qemu:qemu:0.14.0:rc2
  • QEMU 0.1.1
    cpe:2.3:a:qemu:qemu:0.1.1
  • QEMU 0.14.0 release candidate 1
    cpe:2.3:a:qemu:qemu:0.14.0:rc1
  • QEMU 0.1.2
    cpe:2.3:a:qemu:qemu:0.1.2
  • QEMU 0.14.1
    cpe:2.3:a:qemu:qemu:0.14.1
  • QEMU 0.1
    cpe:2.3:a:qemu:qemu:0.1
  • QEMU 0.15.0 release candidate 2
    cpe:2.3:a:qemu:qemu:0.15.0:rc2
  • QEMU 0.1.5
    cpe:2.3:a:qemu:qemu:0.1.5
  • QEMU 0.15.0 release candidate 1
    cpe:2.3:a:qemu:qemu:0.15.0:rc1
  • QEMU 0.1.6
    cpe:2.3:a:qemu:qemu:0.1.6
  • QEMU 0.1.3
    cpe:2.3:a:qemu:qemu:0.1.3
  • QEMU 0.1.4
    cpe:2.3:a:qemu:qemu:0.1.4
  • QEMU 0.11.0-rc0
    cpe:2.3:a:qemu:qemu:0.11.0-rc0
  • QEMU 0.11.0-rc2
    cpe:2.3:a:qemu:qemu:0.11.0-rc2
  • QEMU 0.11.0-rc1
    cpe:2.3:a:qemu:qemu:0.11.0-rc1
CVSS
Base: 2.1 (as of 22-06-2012 - 08:58)
Impact:
Exploitability:
CWE CWE-264
CAPEC
  • Accessing, Modifying or Executing Executable Files
    An attack of this type exploits a system's configuration that allows an attacker to either directly access an executable file, for example through shell access; or in a possible worst case allows an attacker to upload a file and then execute it. Web servers, ftp servers, and message oriented middleware systems which have many integration points are particularly vulnerable, because both the programmers and the administrators must be in synch regarding the interfaces and the correct privileges for each interface.
  • Leverage Executable Code in Non-Executable Files
    An attack of this type exploits a system's trust in configuration and resource files, when the executable loads the resource (such as an image file or configuration file) the attacker has modified the file to either execute malicious code directly or manipulate the target process (e.g. application server) to execute based on the malicious configuration parameters. Since systems are increasingly interrelated mashing up resources from local and remote sources the possibility of this attack occurring is high. The attack can be directed at a client system, such as causing buffer overrun through loading seemingly benign image files, as in Microsoft Security Bulletin MS04-028 where specially crafted JPEG files could cause a buffer overrun once loaded into the browser. Another example targets clients reading pdf files. In this case the attacker simply appends javascript to the end of a legitimate url for a pdf (http://www.gnucitizen.org/blog/danger-danger-danger/) http://path/to/pdf/file.pdf#whatever_name_you_want=javascript:your_code_here The client assumes that they are reading a pdf, but the attacker has modified the resource and loaded executable javascript into the client's browser process. The attack can also target server processes. The attacker edits the resource or configuration file, for example a web.xml file used to configure security permissions for a J2EE app server, adding role name "public" grants all users with the public role the ability to use the administration functionality. The server trusts its configuration file to be correct, but when they are manipulated, the attacker gains full control.
  • Blue Boxing
    This type of attack against older telephone switches and trunks has been around for decades. A tone is sent by an adversary to impersonate a supervisor signal which has the effect of rerouting or usurping command of the line. While the US infrastructure proper may not contain widespread vulnerabilities to this type of attack, many companies are connected globally through call centers and business process outsourcing. These international systems may be operated in countries which have not upgraded Telco infrastructure and so are vulnerable to Blue boxing. Blue boxing is a result of failure on the part of the system to enforce strong authorization for administrative functions. While the infrastructure is different than standard current applications like web applications, there are historical lessons to be learned to upgrade the access control for administrative functions.
  • Restful Privilege Elevation
    Rest uses standard HTTP (Get, Put, Delete) style permissions methods, but these are not necessarily correlated generally with back end programs. Strict interpretation of HTTP get methods means that these HTTP Get services should not be used to delete information on the server, but there is no access control mechanism to back up this logic. This means that unless the services are properly ACL'd and the application's service implementation are following these guidelines then an HTTP request can easily execute a delete or update on the server side. The attacker identifies a HTTP Get URL such as http://victimsite/updateOrder, which calls out to a program to update orders on a database or other resource. The URL is not idempotent so the request can be submitted multiple times by the attacker, additionally, the attacker may be able to exploit the URL published as a Get method that actually performs updates (instead of merely retrieving data). This may result in malicious or inadvertent altering of data on the server.
  • Target Programs with Elevated Privileges
    This attack targets programs running with elevated privileges. The attacker would try to leverage a bug in the running program and get arbitrary code to execute with elevated privileges. For instance an attacker would look for programs that write to the system directories or registry keys (such as HKLM, which stores a number of critical Windows environment variables). These programs are typically running with elevated privileges and have usually not been designed with security in mind. Such programs are excellent exploit targets because they yield lots of power when they break. The malicious user try to execute its code at the same level as a privileged system call.
  • Manipulating Input to File System Calls
    An attacker manipulates inputs to the target software which the target software passes to file system calls in the OS. The goal is to gain access to, and perhaps modify, areas of the file system that the target software did not intend to be accessible.
Access
VectorComplexityAuthentication
LOCAL LOW NONE
Impact
ConfidentialityIntegrityAvailability
PARTIAL NONE NONE
nessus via4
  • NASL family Ubuntu Local Security Checks
    NASL id UBUNTU_USN-1177-1.NASL
    description Andrew Griffiths discovered that QEMU did not correctly drop privileges when using the 'runas' argument. Under certain circumstances a local attacker could exploit this to escalate privileges. 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 2019-01-02
    plugin id 55717
    published 2011-07-28
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=55717
    title Ubuntu 10.04 LTS / 10.10 / 11.04 : qemu-kvm vulnerability (USN-1177-1)
  • NASL family Red Hat Local Security Checks
    NASL id REDHAT-RHSA-2011-1531.NASL
    description Updated qemu-kvm packages that fix one security issue, multiple bugs, and add various enhancements 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. It was found that qemu-kvm did not properly drop supplemental group privileges when the root user started guests from the command line ('/usr/libexec/qemu-kvm') with the '-runas' option. A qemu-kvm process started this way could use this flaw to gain access to files on the host that are accessible to the supplementary groups and not accessible to the primary group. (CVE-2011-2527) Note: This issue only affected qemu-kvm when it was started directly from the command line. It did not affect the Red Hat Enterprise Virtualization platform or applications that start qemu-kvm via libvirt, such as the Virtual Machine Manager (virt-manager). This update also fixes several bugs and adds various enhancements. Documentation for these bug fixes and enhancements will be available shortly from the Technical Notes document, linked to in the References section. All users of qemu-kvm are advised to upgrade to these updated packages, which contain backported patches to correct these issues and add these enhancements. 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 2018-12-20
    plugin id 64006
    published 2013-01-24
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=64006
    title RHEL 6 : qemu-kvm (RHSA-2011:1531)
  • NASL family Debian Local Security Checks
    NASL id DEBIAN_DSA-2282.NASL
    description Two vulnerabilities have been discovered in KVM, a solution for full virtualization on x86 hardware : - CVE-2011-2212 Nelson Elhage discovered a buffer overflow in the virtio subsystem, which could lead to denial of service or privilege escalation. - CVE-2011-2527 Andrew Griffiths discovered that group privileges were insufficiently dropped when started with -runas option, resulting in privilege escalation.
    last seen 2019-02-21
    modified 2018-11-10
    plugin id 55672
    published 2011-07-26
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=55672
    title Debian DSA-2282-1 : qemu-kvm - several vulnerabilities
  • NASL family SuSE Local Security Checks
    NASL id SUSE_11_4_KVM-120124.NASL
    description A missing initgroups() call for the -runas option has been fixed in kvm (CVE-2011-2527) as well as a buffer overflow in the e1000 device emulation (CVE-2012-0029).
    last seen 2019-02-21
    modified 2018-11-10
    plugin id 75889
    published 2014-06-13
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=75889
    title openSUSE Security Update : kvm (openSUSE-SU-2012:0207-1)
  • NASL family Fedora Local Security Checks
    NASL id FEDORA_2012-8604.NASL
    description - CVE-2011-1750 virtio-blk: heap buffer overflow (bz 698906, bz 698911) - CVE-2011-2527 set groups properly for -runas (bz 720773, bz 720784) - CVE-2012-0029 e1000 buffer overflow (bz 783984, bz 772075) - virtio-blk: refuse SG_IO requests with scsi=off (bz 770135) Note that Tenable Network Security has extracted the preceding description block directly from the Fedora 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 2015-10-20
    plugin id 59420
    published 2012-06-08
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=59420
    title Fedora 15 : qemu-0.14.0-9.fc15 (2012-8604)
  • NASL family SuSE Local Security Checks
    NASL id SUSE_11_KVM-120116.NASL
    description The following vulnerabilities have been fixed in KVM : - buffer overflow in e1000 device emulation. (CVE-2012-0029) - missing initgroups() for -runas (CVE-2011-2527)
    last seen 2018-09-02
    modified 2013-10-25
    plugin id 57725
    published 2012-01-30
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=57725
    title SuSE 11.1 Security Update : KVM (SAT Patch Number 5655)
redhat via4
advisories
bugzilla
id 744780
title use-after-free in QEMU SCSI target code
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 2:0.12.1.2-2.209.el6
        oval oval:com.redhat.rhsa:tst:20111531009
      • comment qemu-img is signed with Red Hat redhatrelease2 key
        oval oval:com.redhat.rhsa:tst:20110345008
    • AND
      • comment qemu-kvm is earlier than 2:0.12.1.2-2.209.el6
        oval oval:com.redhat.rhsa:tst:20111531005
      • 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 2:0.12.1.2-2.209.el6
        oval oval:com.redhat.rhsa:tst:20111531007
      • comment qemu-kvm-tools is signed with Red Hat redhatrelease2 key
        oval oval:com.redhat.rhsa:tst:20110345010
rhsa
id RHSA-2011:1531
released 2011-12-06
severity Moderate
title RHSA-2011:1531: qemu-kvm security, bug fix, and enhancement update (Moderate)
rpms
  • qemu-img-2:0.12.1.2-2.209.el6
  • qemu-kvm-2:0.12.1.2-2.209.el6
  • qemu-kvm-tools-2:0.12.1.2-2.209.el6
refmap via4
bid 48659
confirm https://bugs.launchpad.net/qemu/+bug/807893
debian DSA-2282
fedora FEDORA-2012-8604
mlist
  • [oss-security] 20110712 CVE Request: qemu -runas does not clear supplementary groups
  • [oss-security] 20110712 Re: CVE Request: qemu -runas does not clear supplementary groups
osvdb 74752
secunia
  • 45187
  • 45188
  • 45419
  • 47157
  • 47992
suse openSUSE-SU-2012:0207
ubuntu USN-1177-1
xf qemu-runas-priv-escalation(68539)
Last major update 07-12-2016 - 22:02
Published 21-06-2012 - 11:55
Last modified 28-08-2017 - 21:29
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