An issue was discovered in atftpd in atftp 0.7.1. A remote attacker may send a crafted packet triggering a stack-based buffer overflow due to an insecurely implemented strncpy call. The vulnerability is triggered by sending an error packet of 3 bytes or fewer. There are multiple instances of this vulnerable strncpy pattern within the code base, specifically within tftpd_file.c, tftp_file.c, tftpd_mtftp.c, and tftp_mtftp.c.

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.

An exploitable denial of service vulnerability exists in the atftpd daemon functionality of atftp 0.7.git20120829-3.1+b1. A specially crafted sequence of RRQ-Multicast requests trigger an assert() call resulting in denial-of-service. An attacker can send a sequence of malicious packets to trigger this vulnerability.

tftpd_file.c in atftp through 0.7.4 has a buffer overflow because buffer-size handling does not properly consider the combination of data, OACK, and other options.

options.c in atftp before 0.7.5 reads past the end of an array, and consequently discloses server-side /etc/group data to a remote client.