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Fencer Vulns
high 7.5

CVE-2020-17444 json

An issue was discovered in picoTCP 1.7.0.

published 2020-12-11 5 y ago modified 2026-06-17 4 mo ago also EUVD-2020-9397

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
2.8%
EPSS 2.8% chance of exploitation in 30 days, percentile 86%
public exploits
0
none known

Summary

An issue was discovered in picoTCP 1.7.0. The routine for processing the next header field (and deducing whether the IPv6 extension headers are valid) doesn't check whether the header extension length field would overflow. Therefore, if it wraps around to zero, iterating through the extension headers will not increment the current data pointer. This leads to an infinite loop and Denial-of-Service in pico_ipv6_check_headers_sequence() in pico_ipv6.c.

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

cisa ICSA-20-343-01 updated cvss 7.5

Multiple Embedded TCP/IP Stacks

  • multiple open source FNET 4.6.3 multiple open source Nut/Net <= 5.1 multiple open source open-iscsi <= 2.1.12 multiple open source picoTCP (EOL) <= 1.7.0 multiple open source picoTCP-NG <= 1.7.0 multiple open source uIP (EOL) <= 1.0
    +2 more products
    multiple open source uIP-Contiki-NG <= 4.5 multiple open source uIP-Contiki-OS (end-of-life [EOL]) <= 3.0
    affected: vendor fix yanzi.dev

From CISA ICS and IT advisories (CSAF, https://github.com/cisagov/CSAF), a U.S. Government work; changed: reduced to products, statuses and remediations. CISA notification · csaf

Exploit prediction

2.83% chance of exploitation in the next 30 days, higher than 86% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P

Classification

Weakness
  • CWE-20 Improper Input Validation
  • CWE-190 Integer Overflow or Wraparound
  • CWE-835 Loop with Unreachable Exit Condition

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.