Qemu-kvm: qemu-guest-agent: local privilege escalation via symlink attack in guest-ssh-add-authorized-keys

A flaw was found in the QEMU Guest Agent (qga). A local unprivileged user can exploit a vulnerability in the guest-ssh-add-authorized-keys command handler by manipulating symbolic links. This can occur either through a deterministic directory-symlink bypass or a Time-of-Check to Time-of-Use (TOCTOU) file-symlink race. Successful exploitation allows the attacker to gain ownership of arbitrary root-owned files or directories, leading to root access. This vulnerability requires an external management layer (e.g., libvirt) to trigger the affected code path.

Qemu: improper ide controller reset can lead to mbr overwrite

A bug in QEMU could cause a guest I/O operation otherwise addressed to an arbitrary disk offset to be targeted to offset 0 instead (potentially overwriting the VM's boot code). This could be used, for example, by L2 guests with a virtual disk (vdiskL2) stored on a virtual disk of an L1 (vdiskL1) hypervisor to read and/or write data to LBA 0 of vdiskL1, potentially gaining control of L1 at its next reboot.

Qemu: e1000e: heap use-after-free in e1000e_write_packet_to_guest()

A DMA reentrancy issue leading to a use-after-free error was found in the e1000e NIC emulation code in QEMU. This issue could allow a privileged guest user to crash the QEMU process on the host, resulting in a denial of service.

Qemu: vnc: infinite loop in inflate_buffer() leads to denial of service

A flaw was found in the QEMU built-in VNC server while processing ClientCutText messages. A wrong exit condition may lead to an infinite loop when inflating an attacker controlled zlib buffer in the `inflate_buffer` function. This could allow a remote authenticated client who is able to send a clipboard to the VNC server to trigger a denial of service.

Qemu-kvm: virtio-net: queue index out-of-bounds access in software rss

A flaw was found in the virtio-net device in QEMU. When enabling the RSS feature on the virtio-net network card, the indirections_table data within RSS becomes controllable. Setting excessively large values may cause an index out-of-bounds issue, potentially resulting in heap overflow access. This flaw allows a privileged user in the guest to crash the QEMU process on the host.

Qemu-kvm: vhost inflight migration vmstate integer type mismatch causes out-of-bounds access

A type mismatch vulnerability was found in QEMU's vhost inflight migration VMState handling. The destination buffer size is stored as a uint64_t but read by the VMS_VBUFFER load path as a signed int32_t. On little-endian hosts, a crafted incoming migration state with bit 31 set causes the value to be interpreted as negative and then implicitly converted to a very large size_t, leading qemu_get_buffer() to copy migration-stream data beyond the bounds of the mmap-backed inflight region. This can result in a crash of the QEMU process or memory corruption. Exploitation requires control of the migration producer or write access to the migration channel, combined with a destination configured to use vhost inflight migration.

Qemu-kvm: usb: assertion failure in usb_ep_get()

A flaw was found in QEMU. An assertion failure was present in the usb_ep_get() function in hw/net/core.c when trying to get the USB endpoint from a USB device. This flaw may allow a malicious unprivileged guest user to crash the QEMU process on the host and cause a denial of service condition.

Qemu-kvm: net: assertion failure in update_sctp_checksum()

A flaw was found in QEMU. An assertion failure was present in the update_sctp_checksum() function in hw/net/net_tx_pkt.c when trying to calculate the checksum of a short-sized fragmented packet. This flaw allows a malicious guest to crash QEMU and cause a denial of service condition.

Qemu: virtio-net: stack buffer overflow in virtio_net_flush_tx()

A stack based buffer overflow was found in the virtio-net device of QEMU. This issue occurs when flushing TX in the virtio_net_flush_tx function if guest features VIRTIO_NET_F_HASH_REPORT, VIRTIO_F_VERSION_1 and VIRTIO_NET_F_MRG_RXBUF are enabled. This could allow a malicious user to overwrite local variables allocated on the stack. Specifically, the `out_sg` variable could be used to read a part of process memory and send it to the wire, causing an information leak.

Qemu: vnc: null pointer dereference in qemu_clipboard_request()

A flaw was found in the QEMU built-in VNC server while processing ClientCutText messages. The qemu_clipboard_request() function can be reached before vnc_server_cut_text_caps() was called and had the chance to initialize the clipboard peer, leading to a NULL pointer dereference. This could allow a malicious authenticated VNC client to crash QEMU and trigger a denial of service.

Qemu-kvm: 9pfs: use-after-free race in tlcreate/twalk allows vm guest escape

A use-after-free vulnerability was found in QEMU's 9pfs subsystem. A race condition between the main thread and a worker thread when processing concurrent Tlcreate and Twalk requests allows a malicious guest user to craft a fid path containing stale heap data, bypassing directory traversal restrictions and escaping the shared directory boundary. This can lead to arbitrary host file read/write and code execution (VM escape) as the QEMU process user.

Qemu-kvm: vapic writable rom alias can escape the option-rom window and expose locked smram

A flaw was found in QEMU. The VAPIC setup hypercall in hw/i386/vapic.c does not validate that the writable RAM alias remains within the option ROM window. A privileged guest user on a Q35/KVM machine can position this alias over locked SMRAM, bypassing chipset D_LCK protection and injecting code into System Management Mode memory.

Qemu-kvm: hyperv/syndbg: missing mapped-length guard after cpu_physical_memory_map causes host oob write

A flaw was found in QEMU. This vulnerability allows a local attacker within a guest virtual machine to write data beyond its allocated memory. This occurs when cpu_physical_memory_map() returns a shorter length than expected, leading to an out-of-bounds write. Successful exploitation could result in unauthorized access to guest memory or corruption of heap-allocated objects, potentially causing information disclosure, data integrity issues, or a denial of service.

Race Condition Enables VNC Session Hijacking in Proxmox Virtual Environment

A race condition between the vncproxy and vncwebsocket API calls in Proxmox Virtual Environment (PVE) 9.x pve-manager before 9.1.9 and 8.x before 8.4.19; qemu-server 9.x before 9.1.7 and 8.x before 8.4.7; and pve-container before 6.1.3 (PVE 9.x) and before 5.3.4 (PVE 8.x) allows an attacker with privileges to call "vncproxy" to hijack a VNC session that is established in parallel by a different user for a different VM.

Qemu-kvm: virtio-snd: heap buffer overflow in virtio_snd_pcm_in_cb (incomplete fix for cve-2024-7730)

A flaw was found in QEMU. When reading input audio in the virtio-snd device input callback, the `virtio_snd_pcm_in_cb` function did not check whether the iov could fit the data buffer, potentially leading to a heap out-of-bounds write. This issue exists due to an incomplete fix for CVE-2024-7730.

Qemu-kvm: virtio-snd: integer overflow leading to unbounded memory allocation

An integer overflow vulnerability was found in the virtio-snd device via PCM_INFO requests from the guest. A malicious guest can provide out-of-bounds stream counts, potentially leading to unbounded memory allocation on the host and a denial of service condition.

Qemu: sdhci: heap buffer overflow in sdhci_write_dataport()

A heap-based buffer overflow was found in the SDHCI device emulation of QEMU. The bug is triggered when both `s->data_count` and the size of `s->fifo_buffer` are set to 0x200, leading to an out-of-bound access. A malicious guest could use this flaw to crash the QEMU process on the host, resulting in a denial of service condition.

QEMU: rtl8139: integer overflow leads to buffer overflow

Qemu has a Buffer Overflow in rtl8139_do_receive in hw/net/rtl8139.c because an incorrect integer data type is used.

Multiple use-after-free vulnerabilities in vnc.c in the VNC server in QEMU 0.10.6 and earlier might allow guest OS users to execute arbitrary code on the host OS by establishing a connection from a VNC client and then (1) disconnecting during data transfer, (2) sending a message using incorrect integer data types, or (3) using the Fuzzy Screen Mode protocol, related to double free vulnerabilities.

qemu: off-by-one error in monitor.c causing VNC passwords to be truncated after 7th character

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.