No exploitation reportedFix available

CVE-2020-17438

No exploitation reported by the sources we read.

Published2020-12-11
WeaknessCWE-787

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

An issue was discovered in uIP 1.0, as used in Contiki 3.0 and other products. The code that reassembles fragmented packets fails to properly validate the total length of an incoming packet specified in its IP header, as well as the fragmentation offset value specified in the IP header. By crafting a packet with specific values of the IP header length and the fragmentation offset, attackers can write into the .bss section of the program (past the statically allocated buffer that is used for storing the fragmented data) and cause a denial of service in uip_reass() in uip.c, or possibly execute arbitrary code on some target architectures.

Timeline

dates in UTC

2020-12-1123:15CVE publishedNVD
2026-10-2319:23EPSS crossed 10 %FIRST EPSS

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2020-17438?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2020-17438?format=csv
TAXII collection of exploited CVEs
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Versions per branch

NVD

Uip project uipversion to verify

Branch	Affected	Fixed in	Source
1.0	= 1.0	no fix published	NVD

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Vendor advisories

ICSA-20-343-01 CISA8 known affected
Multiple Embedded TCP/IP Stacks
uIP (EOL): Version 1.0 and prior · uIP-Contiki-NG: Version 4.5 and prior · Nut/Net: Version 5.1 and prior · +5 more

Full record on NVD

Fix

Vendor fix CISA ICSA-20-343-01 · 8 productsAdditional vendors affected by the reported vulnerabilities have also released security advisories related to their affected products. Those advisories are as follows:

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

NVDCVSS 3.19.8read 2026-10-23
NVDCVSS 2.07.5read 2026-10-23
NVDweakness (CWE)CWE-787read 2026-10-23
FIRST EPSSEPSS score19.3 %read 2026-10-23

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published: 2020-12-11
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2020-17438?

Is CVE-2020-17438 actively exploited?

Active exploitation of CVE-2020-17438 has not been confirmed. Its EPSS score was 19.3% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2020-17438?

CVE-2020-17438 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

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