An issue was discovered in atftpd in atftp 0.7.1. It does not lock the thread_list_mutex mutex before assigning the current thread data structure. As a result, the daemon is vulnerable to a denial of service attack due to a NULL pointer dereference. If thread_data is NULL when assigned to current, and modified by another thread before a certain tftpd_list.c check, there is a crash when dereferencing current->next.
A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Atftp | Atftp_project | 0.7.1 (including) | 0.7.1 (including) |
| Atftp | Ubuntu | bionic | * |
| Atftp | Ubuntu | cosmic | * |
| Atftp | Ubuntu | disco | * |
| Atftp | Ubuntu | trusty | * |
| Atftp | Ubuntu | xenial | * |