RIOT OS versions up to and including 2026.01-devel-317 contain a stack-based buffer overflow vulnerability in the tapslip6 utility. The vulnerability is caused by unsafe string concatenation in the devopen() function, which constructs a device path using unbounded user-controlled input. The utility uses strcpy() and strcat() to concatenate the fixed prefix '/dev/' with a user-supplied device name provided via the -s command-line option without bounds checking. This allows an attacker to supply an excessively long device name and overflow a fixed-size stack buffer, leading to process crashes and memory corruption.

RIOT OS versions up to and including 2026.01-devel-317 contain a stack-based buffer overflow vulnerability in the ethos utility due to missing bounds checking when processing incoming serial frame data. The vulnerability occurs in the handlechar() function, where incoming frame bytes are appended to a fixed-size stack buffer without verifying that the current write index remains within bounds. An attacker capable of sending crafted serial or TCP-framed input can cause the current write index to exceed the buffer size, resulting in a write past the end of the stack buffer. This condition leads to memory corruption and application crash.

RIOT-OS, an operating system for Internet of Things (IoT) devices, contains a network stack with the ability to process 6LoWPAN frames. In versions 2023.01 and prior, an attacker can send multiple crafted frames to the device to trigger a race condition. The race condition invalidates assumptions about the program state and leads to an invalid memory access resulting in denial of service. This issue is patched in pull request 19679. There are no known workarounds.

RIOT-OS, an operating system for Internet of Things (IoT) devices, contains a network stack with the ability to process 6LoWPAN frames. In version 2023.01 and prior, an attacker can send a crafted frame to the device resulting in an out of bounds write in the packet buffer. The overflow can be used to corrupt other packets and the allocator metadata. Corrupting a pointer will easily lead to denial of service. While carefully manipulating the allocator metadata gives an attacker the possibility to write data to arbitrary locations and thus execute arbitrary code. This issue is fixed in pull request 19680. As a workaround, disable support for fragmented IP datagrams.

RIOT-OS, an operating system for Internet of Things (IoT) devices, contains a network stack with the ability to process 6LoWPAN frames. In versions 2023.01 and prior, an attacker can send a crafted frame which is forwarded by the device. During encoding of the packet a NULL pointer dereference occurs. This crashes the device leading to denial of service. A patch is available at pull request 19678. There are no known workarounds.

In RIOT-OS 2021.01, nonce reuse in 802.15.4 encryption in the ieee820154security component allows attackers to break encryption by triggering reboots.

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 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. 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.

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 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 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 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 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 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 OS version 2020.01.1 is vulnerable to integer wrap-around in its implementation of calloc function, which can lead to arbitrary memory allocation, resulting in unexpected behavior such as a crash or a remote code injection/execution.

RIOT-OS, an operating system that supports Internet of Things devices, contains a network stack with the ability to process 6LoWPAN frames. Prior to version 2022.10, an attacker can send a crafted frame to the device resulting in an out of bounds write in the packet buffer. The overflow can be used to corrupt other packets and the allocator metadata. Corrupting a pointer will easily lead to denial of service. While carefully manipulating the allocator metadata gives an attacker the possibility to write data to arbitrary locations and thus execute arbitrary code. Version 2022.10 fixes this issue. As a workaround, disable support for fragmented IP datagrams or apply the patches manually.

RIOT-OS, an operating system that supports Internet of Things devices, contains a network stack with the ability to process 6LoWPAN frames. Prior to version 2022.10, an attacker can send a crafted frame to the device resulting in a NULL pointer dereference. During forwarding of a fragment an uninitialized entry in the reassembly buffer is used. The NULL pointer dereference triggers a hard fault exception resulting in denial of service. Version 2022.10 fixes this issue. As a workaround, disable support for fragmented IP datagrams or apply the patches manually.

RIOT-OS, an operating system that supports Internet of Things devices, contains a network stack with the ability to process 6LoWPAN frames. An attacker can send a crafted frame to the device resulting in a large out of bounds write beyond the packet buffer. The write will create a hard fault exception after reaching the last page of RAM. The hard fault is not handled and the system will be stuck until reset. Thus the impact is denial of service. Version 2022.10 fixes this issue. As a workaround, apply the patch manually.

RIOT-OS, an operating system that supports Internet of Things devices, contains a network stack with the ability to process 6LoWPAN frames. Prior to version 2022.10, an attacker can send a crafted frame to the device resulting in a large out of bounds write beyond the packet buffer. The write will create a hard fault exception after reaching the last page of RAM. The hard fault is not handled and the system will be stuck until reset, thus the impact is denial of service. Version 2022.10 fixes this issue. As a workaround, disable support for fragmented IP datagrams or apply the patches manually.

RIOT-OS, an operating system that supports Internet of Things devices, contains a network stack with the ability to process 6LoWPAN frames. Prior to version 2022.10, an attacker can send a crafted frame to the device resulting in a NULL pointer dereference while encoding a 6LoWPAN IPHC header. The NULL pointer dereference causes a hard fault exception, leading to denial of service. Version 2022.10 fixes this issue. As a workaround, apply the patches manually.

RIOT-OS, an operating system that supports Internet of Things devices, contains a network stack with the ability to process 6LoWPAN frames. Prior to version 2022.10, an attacker can send a crafted frame to the device resulting in a type confusion between IPv6 extension headers and a UDP header. This occurs while encoding a 6LoWPAN IPHC header. The type confusion manifests in an out of bounds write in the packet buffer. The overflow can be used to corrupt other packets and the allocator metadata. Corrupting a pointer will easily lead to denial of service. While carefully manipulating the allocator metadata gives an attacker the possibility to write data to arbitrary locations and thus execute arbitrary code. Version 2022.10 fixes this issue. As a workaround, apply the patches manually.

RIOT-OS, an operating system for Internet of Things (IoT) devices, contains a network stack with the ability to process 6LoWPAN frames. Prior to version 2023.04, an attacker can send a crafted frame to the device resulting in an integer underflow and out of bounds access in the packet buffer. Triggering the access at the right time will corrupt other packets or the allocator metadata. Corrupting a pointer will lead to denial of service. This issue is fixed in version 2023.04. As a workaround, disable SRH in the network stack.

RIOT-OS, an operating system for Internet of Things (IoT) devices, contains a network stack with the ability to process 6LoWPAN frames. Prior to version 2023.04, an attacker can send a crafted frame to the device to trigger a NULL pointer dereference leading to denial of service. This issue is fixed in version 2023.04. There are no known workarounds.

RIOT-OS, an operating system for Internet of Things (IoT) devices, contains a network stack with the ability to process 6LoWPAN frames. Prior to version 2023.04, an attacker can send crafted frames to the device to trigger the usage of an uninitialized object leading to denial of service. This issue is fixed in version 2023.04. As a workaround, disable fragment forwarding or SFR.

RIOT RIOT-OS version after commit 7af03ab624db0412c727eed9ab7630a5282e2fd3 contains a Buffer Overflow vulnerability in sockdns, an implementation of the DNS protocol utilizing the RIOT sock API that can result in Remote code executing. This attack appears to be exploitable via network connectivity.

In RIOT 2019.07, the MQTT-SN implementation (asymcute) mishandles errors occurring during a read operation on a UDP socket. The receive loop ends. This allows an attacker (via a large packet) to prevent a RIOT MQTT-SN client from working until the device is restarted.

RIOT 2019.07 contains a NULL pointer dereference in the MQTT-SN implementation (asymcute), potentially allowing an attacker to crash a network node running RIOT. This requires spoofing an MQTT server response. To do so, the attacker needs to know the MQTT MsgID of a pending MQTT protocol message and the ephemeral port used by RIOT's MQTT implementation. Additionally, the server IP address is required for spoofing the packet.

In the TCP implementation (gnrctcp) in RIOT through 2019.07, the parser for TCP options does not terminate on all inputs, allowing a denial-of-service, because sys/net/gnrc/transportlayer/tcp/gnrctcpoption.c has an infinite loop for an unknown zero-length option.