Skip to content
Fencer Vulns
high 7.5

CVE-2020-17440 json

An issue was discovered in uIP 1.0, as used in Contiki 3.0 and other products.

published 2020-12-11 5 y ago modified 2026-06-17 4 mo ago also EUVD-2020-9393

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
2.8%
EPSS 2.8% chance of exploitation in 30 days, percentile 86%
public exploits
0
none known

Summary

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.

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

cisa ICSA-20-343-01 updated cvss 7.5

Multiple Embedded TCP/IP Stacks

  • multiple open source FNET 4.6.3 multiple open source Nut/Net <= 5.1 multiple open source open-iscsi <= 2.1.12 multiple open source picoTCP (EOL) <= 1.7.0 multiple open source picoTCP-NG <= 1.7.0 multiple open source uIP (EOL) <= 1.0
    +2 more products
    multiple open source uIP-Contiki-NG <= 4.5 multiple open source uIP-Contiki-OS (end-of-life [EOL]) <= 3.0
    affected: vendor fix yanzi.dev

From CISA ICS and IT advisories (CSAF, https://github.com/cisagov/CSAF), a U.S. Government work; changed: reduced to products, statuses and remediations. CISA notification · csaf

Exploit prediction

2.79% chance of exploitation in the next 30 days, higher than 86% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.