An assertion-failure flaw was found in Qemu before 2.10.1, in the Network Block Device (NBD) servers initial connection negotiation, where the I/O coroutine was undefined. This could crash the qemu-nbd server if a client sent unexpected data during connection negotiation. A remote user or process could use this flaw to crash the qemu-nbd server resulting in denial of service.
The product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Qemu | Qemu | * | 2.10.1 (excluding) |
| Red Hat Enterprise Linux OpenStack Platform 6.0 (Juno) for RHEL 7 | RedHat | qemu-kvm-rhev-10:2.9.0-16.el7_4.11 | * |
| Red Hat Enterprise Linux OpenStack Platform 7.0 (Kilo) for RHEL 7 | RedHat | qemu-kvm-rhev-10:2.9.0-16.el7_4.11 | * |
| Red Hat OpenStack Platform 10.0 (Newton) | RedHat | qemu-kvm-rhev-10:2.9.0-16.el7_4.11 | * |
| Red Hat OpenStack Platform 11.0 (Ocata) | RedHat | qemu-kvm-rhev-10:2.9.0-16.el7_4.11 | * |
| Red Hat OpenStack Platform 8.0 (Liberty) | RedHat | qemu-kvm-rhev-10:2.9.0-16.el7_4.11 | * |
| Red Hat OpenStack Platform 9.0 (Mitaka) | RedHat | qemu-kvm-rhev-10:2.9.0-16.el7_4.11 | * |
| Red Hat Virtualization 4 for Red Hat Enterprise Linux 7 | RedHat | qemu-kvm-rhev-10:2.9.0-16.el7_4.5 | * |
| RHEV 3.X Hypervisor and Agents for RHEL-7 | RedHat | qemu-kvm-rhev-10:2.9.0-16.el7_4.5 | * |
| Qemu | Ubuntu | upstream | * |
| Qemu-kvm | Ubuntu | upstream | * |
While assertion is good for catching logic errors and reducing the chances of reaching more serious vulnerability conditions, it can still lead to a denial of service. For example, if a server handles multiple simultaneous connections, and an assert() occurs in one single connection that causes all other connections to be dropped, this is a reachable assertion that leads to a denial of service.