SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2020-17438

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…

CRITICAL 9.8EPSS 19.3%

Does this matter?

EPSS puts the probability of exploitation in the next 30 days at 19.3%, higher than 97% of all known CVEs. Patch or mitigate before the next change window.

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.

CVSS 3.1
9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
19.29% probability · 97th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-787
Affected
uip project/uip
Source
cve@mitre.org
EPSS trend
0%10%20%3 November 2026: 19.29%3 November 20263 November 2026

EPSS 19.3% since 3 November 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.