CVE-2023-33975 | RIOT-OS vulnerable to Out of Bounds Write in _rbuf_add

Exp

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.

Published: 2023-05-30 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-33975 is rated High Exploit Risk (79/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 1.48%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2023-33975

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2023-33975

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 1.38% 1.48% +0.10%
2 2026-06-08 1.23% 1.38% +0.15%
3 2026-06-07 — 1.23% —

Full EPSS history (20 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-33975

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]

Weakness enumeration for CVE-2023-33975

Affected software / configurations for CVE-2023-33975

Vendor Product Version Raw CPE
riot-os riot <= 2023.01 cpe:2.3:o:riot-os:riot:*:*:*:*:*:*:*:*

References for CVE-2023-33975

URL Tags
https://github.com/RIOT-OS/RIOT/blob/f41b4b67b6affca0a8b32edced7f51088696869a/sys/net/gnrc/network_layer/sixlowpan/frag/rb/gnrc_sixlowpan_frag_rb.c#L320 Vendor Advisory
https://github.com/RIOT-OS/RIOT/blob/f41b4b67b6affca0a8b32edced7f51088696869a/sys/net/gnrc/network_layer/sixlowpan/frag/rb/gnrc_sixlowpan_frag_rb.c#L388 Vendor Advisory
https://github.com/RIOT-OS/RIOT/blob/f41b4b67b6affca0a8b32edced7f51088696869a/sys/net/gnrc/network_layer/sixlowpan/frag/rb/gnrc_sixlowpan_frag_rb.c#L463 Vendor Advisory
https://github.com/RIOT-OS/RIOT/blob/f41b4b67b6affca0a8b32edced7f51088696869a/sys/net/gnrc/network_layer/sixlowpan/frag/rb/gnrc_sixlowpan_frag_rb.c#L467 Vendor Advisory
https://github.com/RIOT-OS/RIOT/blob/f41b4b67b6affca0a8b32edced7f51088696869a/sys/net/gnrc/network_layer/sixlowpan/frag/rb/gnrc_sixlowpan_frag_rb.c#L480 Vendor Advisory
https://github.com/RIOT-OS/RIOT/commit/1aeb90ee5555ae78b567a6365ae4ab71bfd1404b Vendor Advisory
https://github.com/RIOT-OS/RIOT/pull/19680 Patch Vendor Advisory
https://github.com/RIOT-OS/RIOT/security/advisories/GHSA-f6ff-g7mh-58q4 Exploit Vendor Advisory
cvelogic Threat Intelligence