Off-by-one error in monitor.c in Qemu 0.9.1 might make it easier for remote attackers to guess the VNC password, which is limited to seven characters where eight was intended.

Several vulnerabilities have been discovered in kvm, a full virtualization system. The Common Vulnerabilities and Exposures project identifies the following problems :

  - CVE-2008-5714     Chris Webb discovered an off-by-one bug limiting KVM's     VNC passwords to 7 characters. This flaw might make it     easier for remote attackers to guess the VNC password,     which is limited to seven characters where eight was     intended.

  - CVE-2009-3290     It was discovered that the kvm_emulate_hypercall     function in KVM does not prevent access to MMU     hypercalls from ring 0, which allows local guest OS     users to cause a denial of service (guest kernel crash)     and read or write guest kernel memory.

The oldstable distribution (etch) does not contain kvm.

qemu update to version 0.10.1 fixes the following security issues :

CVE-2008-0928: problems with range checks of block devices CVE-2008-1945: problems with removable media handling CVE-2008-2382:
vnc server DoS CVE-2008-4539: fix a heap overflow in the cirrus VGA implementation CVE-2008-5714: off by one error in vnc password handling

Rogue VNC clients could make the built in VNC server of kvm run into an infinite loop (CVE-2008-2382)

An off-by-one bug limited the length of VNC passwords to seven instead of eight (CVE-2008-5714)

Virtualized guests could potentially execute code on the host by triggering a buffer overflow in the network emulation code via large ethernet frames (CVE-2007-5729)

Virtualized guests could potentially execute code on the host by triggering a heap based buffer overflow in the Cirrus Graphics card emulation (CVE-2007-1320).

USN-776-1 fixed vulnerabilities in KVM. Due to an incorrect fix, a regression was introduced in Ubuntu 8.04 LTS that caused KVM to fail to boot virtual machines started via libvirt. This update fixes the problem. We apologize for the inconvenience.

Avi Kivity discovered that KVM did not correctly handle certain disk formats. A local attacker could attach a malicious partition that would allow the guest VM to read files on the VM host. (CVE-2008-1945, CVE-2008-2004)

Alfredo Ortega discovered that KVM's VNC protocol handler did not correctly validate certain messages. A remote attacker could send specially crafted VNC messages that would cause KVM to consume CPU resources, leading to a denial of service. (CVE-2008-2382)

Jan Niehusmann discovered that KVM's Cirrus VGA implementation over VNC did not correctly handle certain bitblt operations. A local attacker could exploit this flaw to potentially execute arbitrary code on the VM host or crash KVM, leading to a denial of service. (CVE-2008-4539)

It was discovered that KVM's VNC password checks did not use the correct length. A remote attacker could exploit this flaw to cause KVM to crash, leading to a denial of service.
(CVE-2008-5714).

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.

Avi Kivity discovered that KVM did not correctly handle certain disk formats. A local attacker could attach a malicious partition that would allow the guest VM to read files on the VM host. (CVE-2008-1945, CVE-2008-2004)

Alfredo Ortega discovered that KVM's VNC protocol handler did not correctly validate certain messages. A remote attacker could send specially crafted VNC messages that would cause KVM to consume CPU resources, leading to a denial of service. (CVE-2008-2382)

Jan Niehusmann discovered that KVM's Cirrus VGA implementation over VNC did not correctly handle certain bitblt operations. A local attacker could exploit this flaw to potentially execute arbitrary code on the VM host or crash KVM, leading to a denial of service.
(CVE-2008-4539)

It was discovered that KVM's VNC password checks did not use the correct length. A remote attacker could exploit this flaw to cause KVM to crash, leading to a denial of service. (CVE-2008-5714).

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.

Security vulnerabilities have been discovered and corrected in VNC server of qemu version 0.9.1 and earlier, which could lead to denial-of-service attacks (CVE-2008-2382), and make it easier for remote crackers to guess the VNC password (CVE-2008-5714).

The updated packages have been patched to prevent this.

Security vulnerabilities have been discovered and corrected in VNC server of kvm version 79 and earlier, which could lead to denial-of-service attacks (CVE-2008-2382), and make it easier for remote crackers to guess the VNC password (CVE-2008-5714).

The updated packages have been patched to prevent this.

ID	Name	Product	Family	Severity
44772	Debian DSA-1907-1 : kvm - several vulnerabilities	Nessus	Debian Local Security Checks	high
40302	openSUSE Security Update : qemu (qemu-691)	Nessus	SuSE Local Security Checks	high
40254	openSUSE Security Update : kvm (kvm-412)	Nessus	SuSE Local Security Checks	high
40118	openSUSE Security Update : qemu (qemu-691)	Nessus	SuSE Local Security Checks	high
40019	openSUSE Security Update : kvm (kvm-412)	Nessus	SuSE Local Security Checks	high
38777	Ubuntu 8.04 LTS : kvm regression (USN-776-2)	Nessus	Ubuntu Local Security Checks	high
38759	Ubuntu 8.04 LTS / 8.10 : kvm vulnerabilities (USN-776-1)	Nessus	Ubuntu Local Security Checks	high
36993	Mandriva Linux Security Advisory : qemu (MDVSA-2009:008)	Nessus	Mandriva Local Security Checks	high
36990	Mandriva Linux Security Advisory : kvm (MDVSA-2009:009)	Nessus	Mandriva Local Security Checks	high
36082	openSUSE 10 Security Update : qemu (qemu-6123)	Nessus	SuSE Local Security Checks	high

Detections

Analytics

CVE-2008-5714

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Tenable Plugins

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