Security advisory
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.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2020-17438
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 06:56 UTC · Revision 1
Source evidence
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.
osv:CVE-2020-17438
Complete source record
{
"id": "4e16a160b11aa4c4eadd0a8dfb8605fad4f7198c8074e5ab80be3138106b381f",
"url": "https://osv.dev/vulnerability/CVE-2020-17438",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2020-17438",
"summary": "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.",
"evidence": "osv:CVE-2020-17438",
"products": [],
"severity": "critical",
"structured": {
"id": "CVE-2020-17438",
"aliases": [
"CVE-2020-17438"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/adamdunkels/uip",
"type": "GIT",
"events": [
{
"introduced": "a49def743f6e5c7d0c0f2d724f0b8e0c563a4a37"
},
{
"last_affected": "a49def743f6e5c7d0c0f2d724f0b8e0c563a4a37"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:uip_project:uip:1.0:*:*:*:*:*:*:*",
"range": [
{
"introduced": "1.0"
},
{
"last_affected": "1.0"
}
],
"source": "CPE_STRING"
}
]
}
}
],
"versions": [
"1.0",
"uip-1-0"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-17438.json"
}
}
],
"modified": "2026-10-24T10:30:46.670590194Z",
"provider": "osv",
"references": [
"https://us-cert.cisa.gov/ics/advisories/icsa-20-343-01",
"https://www.kb.cert.org/vuls/id/815128"
],
"provider_metadata": {}
},
"related_cves": [
{
"value": "CVE-2020-17438",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 436384,
"published_at": "2020-12-11T23:15:12.747+00:00"
}