RIOT is a real-time multi-threading operating system that supports a range of devices that are typically 8-bit, 16-bit and 32-bit microcontrollers. The size check in the gcoapdnsserverproxyget() function contains a small typo that may lead to a buffer overflow in the subsequent strcpy(). In detail, the length of the uri string is checked instead of the length of the proxy string. The gcoapforwardproxycopyoptions() function does not implement an explicit size check before copying data to the cep->reqetag buffer that is COAPETAGLENGTHMAX bytes long. If an attacker can craft input so that optlen becomes larger than COAPETAGLENGTHMAX, they can cause a buffer overflow. If the input above is attacker-controlled and crosses a security boundary, the impact of the buffer overflow vulnerabilities could range from denial of service to arbitrary code execution. This issue has yet to be patched. Users are advised to add manual bounds checking.

RIOT-OS, an operating system that supports Internet of Things devices, has an ineffective size check implemented with assert() can lead to buffer overflow in versions up to and including 2025.04. Assertions are usually compiled out in production builds. If assertions are the only defense against untrusted inputs, the software may be exposed to attacks that utilize the lack of proper input checks. In the l2filteradd() function shown below, addrlen is checked using an assertion and is subsequently used as an argument in a memcpy() call. When assertions are disabled, there would be no size check for addrlen. As a consequence, if an attacker were to provide an addrlen value larger than CONFIGL2FILTERADDRMAXLEN, they can trigger a buffer overflow and write past the list[i].addr buffer. If the unchecked input is attacker-controlled, the impact of the buffer overflow can range from a denial of service to arbitrary code execution. Commit f6f7de4ccc107c018630e4c15500825caf02e1c2 contains a patch for the vulnerability.

RIOT is an open-source microcontroller operating system, designed to match the requirements of Internet of Things (IoT) devices and other embedded devices. A vulnerability was discovered in the IPv6 fragmentation reassembly implementation of RIOT OS v2025.07. When copying the contents of the first fragment (offset=0) into the reassembly buffer, no size check is performed. It is possible to force the creation of a small reassembly buffer by first sending a shorter fragment (also with offset=0). Overflowing the reassembly buffer corrupts the state of other packet buffers which an attacker might be able to used to achieve further memory corruption (potentially resulting in remote code execution). To trigger the vulnerability, the gnrcipv6extfrag module must be included and the attacker must be able to send arbitrary IPv6 packets to the victim. Version 2025.10 fixes the issue.

RIOT is an open-source microcontroller operating system, designed to match the requirements of Internet of Things (IoT) devices and other embedded devices. In 2026.01 and earlier, the default handler for the wellknowncore resource coapwellknowncoredefaulthandler writes user-provided option data and other data into a fixed size buffer without validating the buffer is large enough to contain the response. This vulnerability allows an attacker to corrupt neighboring stack location, including security-sensitive addresses like the return address, leading to denial of service or arbitrary code execution.

RIOT is an open-source microcontroller operating system, designed to match the requirements of Internet of Things (IoT) devices and other embedded devices. In version 2025.10 and prior, multiple out-of-bounds read allow any unauthenticated user, with ability to send or manipulate input packets, to read adjacent memory locations, or crash a vulnerable device running the 6LoWPAN stack. The received packet is cast into a sixlowpansfrrfragt struct and dereferenced without validating the packet is large enough to contain the struct object. At time of publication, no known patch exists.

RIOT is a real-time multi-threading operating system that supports a range of devices that are typically 8-bit, 16-bit and 32-bit microcontrollers. Most codebases define assertion macros which compile to a no-op on non-debug builds. If assertions are the only line of defense against untrusted input, the software may be exposed to attacks that leverage the lack of proper input checks. In detail, in the nimblescanlistupdate() function below, len is checked in an assertion and subsequently used in a call to memcpy(). If an attacker is able to provide a larger len value while assertions are compiled-out, they can write past the end of the fixed-length e->ad buffer. If the unchecked input above is attacker-controlled and crosses a security boundary, the impact of the buffer overflow vulnerability could range from denial of service to arbitrary code execution. This issue has not yet been patched. Users are advised to add manual len checking.

RIOT is a real-time multi-threading operating system that supports a range of devices that are typically 8-bit, 16-bit and 32-bit microcontrollers. The onrdinit() function does not implement a size check before copying data to the resultbuf static buffer. If an attacker can craft a long enough payload, they could cause a buffer overflow. If the unchecked input above is attacker-controlled and crosses a security boundary, the impact of the buffer overflow vulnerability could range from denial of service to arbitrary code execution. This issue has yet to be patched. Users are advised to add manual bounds checking.

RIOT is an operating system for internet of things (IoT) devices. In version 2024.04 and prior, the function parseadvertise, located in /sys/net/applicationlayer/dhcpv6/client.c, has no minimum header length check for dhcpv6optt after processing dhcpv6msgt. This omission could lead to an out-of-bound read, causing system inconsistency. Additionally, the same lack of a header length check is present in the function preparseadvertise, which is called by parseadvertise before handling the request. As of time of publication, no known patched version exists.

RIOT is an open-source microcontroller operating system, designed to match the requirements of Internet of Things (IoT) devices and other embedded devices. A malicious actor can send a IEEE 802.15.4 packet with spoofed length byte and optionally spoofed FCS, which eventually results into an endless loop on a CC2538 as receiver. Before PR #20998, the receiver would check for the location of the CRC bit using the packet length byte by considering all 8 bits, instead of discarding bit 7, which is what the radio does. This then results into reading outside of the RX FIFO. Although it prints an error when attempting to read outside of the RX FIFO, it will continue doing this. This may lead to a discrepancy in the CRC check according to the firmware and the radio. If the CPU judges the CRC as correct and the radio is set to AUTOACK, when the packet requests and acknowledgment the CPU will go into the state CC2538STATETXACK. However, if the radio judged the CRC as incorrect, it will not send an acknowledgment, and thus the TXACKDONE event will not fire. It will then never return to the state CC2538STATEREADY since the baseband processing is still disabled. Then the CPU will be in an endless loop. Since setting to idle is not forced, it won't do it if the radio's state is not CC2538STATEREADY. A fix has not yet been made.

RIOT is an open-source microcontroller operating system, designed to match the requirements of Internet of Things (IoT) devices and other embedded devices. A vulnerability was discovered in the IPv6 fragmentation reassembly implementation of RIOT OS v2025.07. When receiving an fragmented IPv6 packet with fragment offset 0 and an empty payload, the payload pointer is set to NULL. However, the implementation still tries to copy the payload into the reassembly buffer, resulting in a NULL pointer dereference which crashes the OS (DoS). To trigger the vulnerability, the gnrcipv6extfrag module must be enabled and the attacker must be able to send arbitrary IPv6 packets to the victim. RIOT OS v2025.10 fixes the issue.