CVE-2020-17439

highpriority · track · 34stack campaign · AMNESIA:33EPSS 0.032 · 88 %ileDEEUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

3.18% (88th) EPSS

CVSS 7.5 · high

Is it mine?

28 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · cert_bund · cisa_csaf_ot

EPSS · scored 2026-10-27

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 the incoming DNS replies match outgoing DNS queries in newdata() in resolv.c. Also, arbitrary DNS replies are parsed if there was any outgoing DNS query with a transaction ID that matches the transaction ID of an incoming reply. Provided that the default DNS cache is quite small (only four records) and that the transaction ID has a very limited set of values that is quite easy to guess, this can lead to DNS cache poisoning.

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

FixedFNETcisa_csaf_ot
Additional vendors affected by the reported vulnerabilities have also released security advisories related to their affected products. Those advisories are as follows:
https://yanzi.dev/#/security/advisories/2020-12-08
FixedNut/Netcisa_csaf_ot
Additional vendors affected by the reported vulnerabilities have also released security advisories related to their affected products. Those advisories are as follows:
https://yanzi.dev/#/security/advisories/2020-12-08
Fixedopen-iscsicisa_csaf_ot
Additional vendors affected by the reported vulnerabilities have also released security advisories related to their affected products. Those advisories are as follows:
https://yanzi.dev/#/security/advisories/2020-12-08
FixedpicoTCP (EOL)cisa_csaf_ot
Additional vendors affected by the reported vulnerabilities have also released security advisories related to their affected products. Those advisories are as follows:
https://yanzi.dev/#/security/advisories/2020-12-08
FixedpicoTCP-NGcisa_csaf_ot
Additional vendors affected by the reported vulnerabilities have also released security advisories related to their affected products. Those advisories are as follows:
https://yanzi.dev/#/security/advisories/2020-12-08
FixeduIP (EOL)cisa_csaf_ot
Additional vendors affected by the reported vulnerabilities have also released security advisories related to their affected products. Those advisories are as follows:
https://yanzi.dev/#/security/advisories/2020-12-08
FixeduIP-Contiki-NGcisa_csaf_ot
Additional vendors affected by the reported vulnerabilities have also released security advisories related to their affected products. Those advisories are as follows:
https://yanzi.dev/#/security/advisories/2020-12-08
FixeduIP-Contiki-OS (end-of-life [EOL])cisa_csaf_ot
Additional vendors affected by the reported vulnerabilities have also released security advisories related to their affected products. Those advisories are as follows:
https://yanzi.dev/#/security/advisories/2020-12-08

cvss

Technical severity, 0–10. One row per scoring source.

8.3

010

base score 0–10 · higher = more severe · hover a vector to decode

v2.07.5highAV:N/AC:L/Au:N/C:P/I:P/A:Pprimary · NVD / NIST USexploitability 10 · impact 6.4

v3.18.3highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:Lprimary · NVD / NIST USexploitability 3.9 · impact 3.7

v3.08.1highCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:L/A:Lsecondary · CISA US

v3.17.6highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:L/E:Usecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-20USprimaryCWE-20US

affected products (28)

Products and version ranges known to be affected.

Open Source TCP/IP Stackall versionscert_bundDEcpe:/a:open_source:tcpip_stack:-
SUSE Linuxall versionscert_bundDEcpe:/o:suse:suse_linux:-
Ubuntu Linuxall versionscert_bundDEcpe:/o:canonical:ubuntu_linux:-
Unify OpenScape 4000all versionscert_bundDEcpe:/h:unify:openscape_4000:-
Unify OpenScape Alarm Responseall versionscert_bundDEcpe:/h:unify:openscape_alarm_response:-
Unify OpenScape Businessall versionscert_bundDEcpe:/a:unify:openscape_business:-
Unify OpenScape Common Management Platformall versionscert_bundDEcpe:/a:unify:openscape_common_management_platform:-
Unify OpenScape Cordless IPall versionscert_bundDEcpe:/a:unify:openscape_cordless_ip:-
Unify OpenScape Desk Phoneall versionscert_bundDEcpe:/h:unify:openscape_deskphone:-
Unify OpenScape Xpertall versionscert_bundDEcpe:/h:unify:openscape_xpert:-
FNET: Version 4.6.3all versionscisa_csaf_otUS
Nut/Net: Version 5.1 and priorall versionscisa_csaf_otUS
open-iscsi: Version 2.1.12 and priorall versionscisa_csaf_otUS
picoTCP (EOL): Version 1.7.0 and priorall versionscisa_csaf_otUS
picoTCP-NG: Version 1.7.0 and priorall versionscisa_csaf_otUS
uIP (EOL): Version 1.0 and priorall versionscisa_csaf_otUS
uIP-Contiki-NG: Version 4.5 and priorall versionscisa_csaf_otUS
uIP-Contiki-OS (end-of-life [EOL]): Version 3.0 and priorall versionscisa_csaf_otUS
multiple open source FNETall versionscisa_csaf_otUS
multiple open source Nut/Net≤ 5.1cisa_csaf_otUS

showing 20 of 28

advisories (2)

Vendor and ecosystem advisories describing this.

WID-SEC-W-2022-1044TCP/IP Stack: Mehrere SchwachstellenDeutsch2020-12-08csaf · cert_bundDE
Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in TCP/IP Stack ausnutzen, um beliebigen Programmcode mit Administratorrechten auszuführen, einen Denial of Service Angriff durchzuführen, vertrauliche Daten einzusehen oder Daten zu manipulieren.
ICSA-20-343-01Multiple Embedded TCP/IP Stacks2020-12-08icsa · cisa_csaf_otUS
Successful exploitation of these vulnerabilities could allow attackers to corrupt memory, put devices into infinite loops, access unauthorized data, and/or poison DNS cache.

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd cert_bund cisa_csaf_ot NVD CVE.org MITRE

published 2020-12-11modified 2026-06-17

related (25,176)

Related entries.

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+25171 more

references (8)

External citations — patches, advisories, analysis.

https://nvd.nist.gov/vuln/detail/CVE-2020-17439 cnnvd
https://us-cert.cisa.gov/ics/advisories/icsa-20-343-01 cnnvd
https://www.auscert.org.au/bulletins/ESB-2020.4363/cnnvd
https://www.kb.cert.org/vuls/id/815128 cnnvd
https://us-cert.cisa.gov/ics/advisories/icsa-20-343-01 enisa_euvd
https://www.kb.cert.org/vuls/id/815128 enisa_euvd
https://us-cert.cisa.gov/ics/advisories/icsa-20-343-01Third Party AdvisoryUS Government Resourcenvd
https://www.kb.cert.org/vuls/id/815128Third Party AdvisoryUS Government Resourcenvd

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