A flaw was found in avahi 0.8-5. A reachable assertion is present in avahi_s_host_name_resolver_start function allowing a local attacker to crash the avahi service by requesting hostname resolutions through the avahi socket or dbus methods for invalid hostnames. The highest threat from this vulnerability is to the service availability.
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 |
|---|---|---|---|
| Avahi | Avahi | 0.8-5 (including) | 0.8-5 (including) |
| Avahi | Ubuntu | devel | * |
| Avahi | Ubuntu | groovy | * |
| Avahi | Ubuntu | hirsute | * |
| Avahi | Ubuntu | impish | * |
| Avahi | Ubuntu | jammy | * |
| Avahi | Ubuntu | precise/esm | * |
| Avahi | Ubuntu | trusty | * |
| Red Hat Enterprise Linux 9 | RedHat | avahi-0:0.8-15.el9 | * |
| Red Hat Enterprise Linux 9 | RedHat | avahi-0:0.8-15.el9 | * |
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.