CVE-2023-37281 | Out-of-bounds read during IPHC address decompression

Contiki-NG is an operating system for internet-of-things devices. In versions 4.9 and prior, when processing the various IPv6 header fields during IPHC header decompression, Contiki-NG confirms the received packet buffer contains enough data as needed for that field. But no similar check is done before decompressing the IPv6 address. Therefore, up to 16 bytes can be read out of bounds on the line with the statement `memcpy(&ipaddr->u8[16 - postcount], iphc_ptr, postcount);`. The value of `postcount` depends on the address compression used in the received packet and can be controlled by the attacker. As a result, an attacker can inject a packet that causes an out-of-bound read. As of time of publication, a patched version is not available. As a workaround, one can apply the changes in Contiki-NG pull request #2509 to patch the system.

Published: 2023-09-15 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-37281 is rated Low Risk (32/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.39%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

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-2023-37281

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 0.16% 0.39% +0.22%
2 2025-03-17 0.05% 0.16% +0.11%
3 2024-08-15 — 0.05% —

Full EPSS history (4 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-37281

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N 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:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 1.4 [email protected]
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N 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:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 1.4 [email protected]

Weakness enumeration for CVE-2023-37281

Affected software / configurations for CVE-2023-37281

Vendor Product Version Raw CPE
contiki-ng contiki-ng <= 4.9 cpe:2.3:o:contiki-ng:contiki-ng:*:*:*:*:*:*:*:*

References for CVE-2023-37281

cvelogic Threat Intelligence