67 matches found
Xen Hypervisor Memory Leak on Boot (XSA-235)
According to its self-reported version number, the Xen hypervisor installed on the remote host is affected by flaw within the pagealloc.c and asm-arm/numa.h due to not scrubbing the memory on boot. This could potentially leave sensitive information available to read after a reboot. This issue onl...
cxenstored: Race in domain cleanup
ISSUE DESCRIPTION When shutting down a VM with a stubdomain, a race in cxenstored may cause a double-free. IMPACT The xenstored daemon may crash, resulting in a DoS of any parts of the system relying on it including domain creation / destruction, ballooning, device changes, etc. VULNERABLE SYSTEM...
Xen Hypervisor Function Error Condition Handling Lock Release Failure Guest-to-Host DoS (XSA-235)
According to its self-reported version number, the Xen hypervisor installed on the remote host is affected by flaw in the xenmemaddtophysmapone function in arch/arm/mm.c that is triggered as the application fails to release a lock when handling certain error conditions. This may allow a privilege...
Xen CMPXCHG8B Emulation Information Disclosure (XSA-200)
According to its self-reported version number, the Xen hypervisor installed on the remote host is missing a security update. It is, therefore, affected by an information disclosure vulnerability due to a flaw in the x86 instruction CMPXCHG8B when handling prefixes. This is triggered because legac...
qemu ioport array overflow
ISSUE DESCRIPTION The code in qemu which implements ioport read/write looks up the specified ioport address in a dispatch table. The argument to the dispatch function is a uint32t, and is used without a range check, even though the table has entries for only 2^16 ioports. When qemu is used as a...
x86 null segments not always treated as unusable
ISSUE DESCRIPTION The Xen x86 emulator erroneously failed to consider the unusability of segments when performing memory accesses. The intended behaviour is as follows: The user data segment %ds, %es, %fs and %gs selectors may be NULL in 32-bit to prevent access. In 64-bit, NULL has a special...
Debian Security Advisory DSA 3633-1 (xen - security update)
Multiple vulnerabilities have been discovered in the Xen hypervisor. The Common Vulnerabilities and Exposures project identifies the following problems: CVE-2015-8338 Julien Grall discovered that Xen on ARM was susceptible to denial of service via long running memory operations. CVE-2016-4480 Jan...
Unrestricted qemu logging
ISSUE DESCRIPTION When the libxl toolstack launches qemu for HVM guests, it pipes the output of stderr to a file in /var/log/xen. This output is not rate-limited in any way. The guest can easily cause qemu to print messages to stderr, causing this file to become arbitrarily large. IMPACT The disk...
qemu-dm buffer overrun in MSI-X handling
ISSUE DESCRIPTION "qemu-xen-traditional" aka qemu-dm tracks state for each MSI-X table entry of a passed through device. This is used/updated on intercepted accesses to the pages containing the MSI-X table. There may be space on the final page not covered by any MSI-X table entry, but memory for...
arm: Race between domain destruction and memory allocation decrease
ISSUE DESCRIPTION While freeing the memory associated with a domain during domain destruction Xen could race with a toolstack domain reducing the amount of memory associated with that same domain via the XENMEMdecreasereservation. In the case where this race is hit the host will crash. The race i...
Potential unintended writes to host MSI message data field via qemu
ISSUE DESCRIPTION Logic is in place to avoid writes to certain host config space fields when the guest must nevertheless be able to access their virtual counterparts. A bug in how this logic deals with accesses spanning multiple fields allows the guest to write to the host MSI message data field...
Information leak through XEN_DOMCTL_gettscinfo
ISSUE DESCRIPTION The handler for XENDOMCTLgettscinfo failed to initialize a padding field subsequently copied to guest memory. A similar bug existed in XENSYSCTLgetdomaininfolist, which is addressed by the patches provided here even though that operation was declared by XSA-77 not to provide...
Unmediated PCI command register access in qemu
ISSUE DESCRIPTION HVM guests are currently permitted to modify the memory and I/O decode bits in the PCI command register of devices passed through to them. Unless the device is an SR-IOV virtual function, after disabling one or both of these bits subsequent accesses to the MMIO or I/O port range...
Excessive checking in compatibility mode hypercall argument translation
ISSUE DESCRIPTION The hypercall argument translation needed for 32-bit guests running on 64-bit hypervisors performs checks on the final register state. These checks cover all registers potentially holding hypercall arguments, not just the ones actually doing so for the hypercall being processed,...
Guest effectable page reference leak in MMU_MACHPHYS_UPDATE handling
ISSUE DESCRIPTION An error handling path in the processing of MMUMACHPHYSUPDATE failed to drop a page reference which was acquired in an earlier processing step. IMPACT Malicious or buggy stub domain kernels or tool stacks otherwise living outside of Domain0 can mount a denial of service attack...
CVE-2014-5147
Xen 4.4.x, when running a 64-bit kernel on an ARM system, does not properly handle traps from the guest domain that use a different address width, which allows local guest users to cause a denial of service host crash via a crafted 32-bit process...
unexpected pitfall in xenaccess API
ISSUE DESCRIPTION A test/example program, for exercising the Xen memaccess API, does not take all necessary precautions against hostile guest behaviour. As a result, software developers using it as an example or template might have written and deployed vulnerable code. See the patch for technical...
CVE-2014-3717
Xen 4.4.x does not properly validate the load address for 64-bit ARM guest kernels, which allows local users to read system memory or cause a denial of service crash via a crafted kernel, which triggers a buffer overflow...