CVE-2020-17438

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.

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-2020-17438 is rated Moderate Risk (63.5/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 0.82%). 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-2020-17438

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 2.36% 0.82% -1.54%
2 2025-05-07 0.60% 2.36% +1.76%
3 2025-04-02 — 0.60% —

Full EPSS history (14 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-17438

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]
7.5 2.0 HIGH
AV:N/AC:L/Au:N/C:P/I:P/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:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 6.4 [email protected]

Weakness enumeration for CVE-2020-17438

OS Trackers for CVE-2020-17438

vendor priority summary link
suse high CVE-2020-17438 severity important: SUSE including 60 source package names (0.38.1.5.8.40:libopeniscsiusr0_2_0-2.1.4-22.14.1, 0.38.1.5.8.40:open-iscsi-2.1.4-22.14.1, …), 208 product×package rows across 59 product lines (Container suse/sles/15.2/virt-launcher, Image SLES12-SP5-Azure-BYOS, … (59 product lines)): Fixed 198, Known Not Affected 10. https://www.suse.com/security/cve/CVE-2020-17438/
ubuntu medium CVE-2020-17438 medium priority: Ubuntu including 1 source packages (open-iscsi), 6 status rows across 6 suites (bionic, focal, groovy, trusty, upstream, xenial): not-affected 6. https://ubuntu.com/security/CVE-2020-17438

Affected software / configurations for CVE-2020-17438

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

References for CVE-2020-17438

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