CVE-2023-34101 | Contiki-NG vulnerable to out-of-bounds read when processing ICMP DAO input

Contiki-NG is an operating system for internet of things devices. In version 4.8 and prior, when processing ICMP DAO packets in the `dao_input_storing` function, the Contiki-NG OS does not verify that the packet buffer is big enough to contain the bytes it needs before accessing them. Up to 16 bytes can be read out of bounds in the `dao_input_storing` function. An attacker can truncate an ICMP packet so that it does not contain enough data, leading to an out-of-bounds read on these lines. The problem has been patched in the "develop" branch of Contiki-NG, and is expected to be included in release 4.9. As a workaround, one can apply the changes in Contiki-NG pull request #2435 to patch the system.

Published: 2023-06-14 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2023-34101 is rated Moderate Risk (43.2/100): CVSS High severity, with low exploitation likelihood (EPSS 0.51%). Mandatory action: Review affected assets and schedule remediation.

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

Exploit prediction scoring system (EPSS) score for CVE-2023-34101

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 0.15% 0.51% +0.35%
2 2025-11-21 0.49% 0.15% -0.34%
3 2025-11-18 0.49%

Full EPSS history (10 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-34101

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.3 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L 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:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
3.9 3.4 [email protected]
9.1 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/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:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
3.9 5.2 [email protected]

Weakness enumeration for CVE-2023-34101

Affected software / configurations for CVE-2023-34101

Vendor Product Version Raw CPE
contiki-ng contiki-ng <= 4.8 cpe:2.3:o:contiki-ng:contiki-ng:*:*:*:*:*:*:*:*

References for CVE-2023-34101

cvelogic Threat Intelligence