In PicoTCP 1.7.0, TCP ISNs are improperly random.

VirtualSquare picoTCP (aka PicoTCP-NG) through 2.1 does not properly check whether header sizes would result in accessing data outside of a packet.

VirtualSquare picoTCP (aka PicoTCP-NG) through 2.1 lacks certain size calculations before attempting to set a value of an mss structure member.

VirtualSquare picoTCP (aka PicoTCP-NG) through 2.1 does not have an MSS lower bound (e.g., it could be zero).

VirtualSquare picoTCP (aka PicoTCP-NG) through 2.1 does not check the transport layer length in a frame before performing port filtering.

Altran picoTCP through 1.7.0 allows memory corruption (and subsequent denial of service) because of an integer overflow in pico_ipv6_alloc when processing large ICMPv6 packets. This affects installations with Ethernet support in which a packet size greater than 65495 may occur.

Double Free vulnerability in virtualsquare picoTCP v1.7.0 and picoTCP-NG v2.1 in modules/pico_fragments.c in function pico_fragments_reassemble, allows attackers to execute arbitrary code.

An issue was discovered in picoTCP 1.7.0. The code for processing the IPv6 destination options does not check for a valid length of the destination options header. This results in an Out-of-Bounds Read, and, depending on the memory protection mechanism, this may result in Denial-of-Service in pico_ipv6_process_destopt() in pico_ipv6.c.

An issue was discovered in picoTCP 1.7.0. The code for processing the IPv6 headers does not validate whether the IPv6 payload length field is equal to the actual size of the payload, which leads to an Out-of-Bounds read during the ICMPv6 checksum calculation, resulting in either Denial-of-Service or Information Disclosure. This affects pico_ipv6_extension_headers and pico_checksum_adder (in pico_ipv6.c and pico_frame.c).

An issue was discovered in picoTCP 1.7.0. The code for creating an ICMPv6 echo replies doesn't check whether the ICMPv6 echo request packet's size is shorter than 8 bytes. If the size of the incoming ICMPv6 request packet is shorter than this, the operation that calculates the size of the ICMPv6 echo replies has an integer wrap around, leading to memory corruption and, eventually, Denial-of-Service in pico_icmp6_send_echoreply_not_frag in pico_icmp6.c.