In ACCEL-PPP (an implementation of PPTP/PPPoE/L2TP/SSTP), there is a buffer overflow when receiving an l2tp control packet ith an AVP which type is a string and no hidden flags, length set to less than 6. If your application is used in open networks or there are untrusted nodes in the network it is highly recommended to apply the patch. The problem was patched with commit 2324bcd5ba12cf28f47357a8f03cd41b7c04c52b As a workaround changes of commit 2324bcd5ba12cf28f47357a8f03cd41b7c04c52b can be applied to older versions.

Variable underflow exists in accel-ppp radius/packet.c when receiving a RADIUS vendor-specific attribute with length field is less than 2. It has an impact only when the attacker controls the RADIUS server, which can lead to arbitrary code execution.

ACCEL-PPP 1.12.0 has an out-of-bounds read in triton_context_schedule if the client exits after authentication.

ACCEL-PPP 1.12.0 has an out-of-bounds read in post_msg when processing a call_clear_request.

The telnet_input_char function in opt/src/accel-pppd/cli/telnet.c suffers from a memory corruption vulnerability, whereby user input cmdline_len is copied into a fixed buffer b->buf without any bound checks. If the server connects with a malicious client, crafted client requests can remotely trigger this vulnerability.

The rad_packet_recv function in opt/src/accel-pppd/radius/packet.c suffers from a buffer overflow vulnerability, whereby user input len is copied into a fixed buffer &attr->val.integer without any bound checks. If the client connects to the server and sends a large radius packet, a buffer overflow vulnerability will be triggered.