CVE-2020-17440

An issue was discovered in uIP 1.0, as used in Contiki 3.0 and other products. The code that parses incoming DNS packets does not validate that domain names present in the DNS responses have '\0' termination. This results in errors when calculating the offset of the pointer that jumps over domain name bytes in DNS response packets when a name lacks this termination, and eventually leads to dereferencing the pointer at an invalid/arbitrary address, within newdata() and parse_name() in resolv.c.

Published: 2020-12-11 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-17440 is rated Moderate Risk (53.9/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.58%). 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-2020-17440

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 2025-12-13 0.45% 0.58% +0.13%
2 2025-03-17 0.08% 0.45% +0.36%
3 2023-03-07 — 0.08% —

Full EPSS history (7 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-17440

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/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:N)
Doesn’t really leak secrets in a meaningful 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 3.6 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2020-17440

Affected software / configurations for CVE-2020-17440

Vendor Product Version Raw CPE
uip_project uip 1.0 cpe:2.3:a:uip_project:uip:1.0:*:*:*:*:*:*:*

References for CVE-2020-17440

URL Tags
https://us-cert.cisa.gov/ics/advisories/icsa-20-343-01 Third Party Advisory US Government Resource
https://www.kb.cert.org/vuls/id/815128 Third Party Advisory US Government Resource
cvelogic Threat Intelligence