CVE-2021-21971 json
An out-of-bounds write vulnerability exists in the URL_decode functionality of Sealevel Systems, Inc.
published 2022-02-04 4 y ago modified 2026-06-17 4 mo ago also EUVD-2021-9142
- cvss
- 3.7
- version 3.0, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.7%
- EPSS 0.7% chance of exploitation in 30 days, percentile 53%
- public exploits
- 0
- none known
Summary
An out-of-bounds write vulnerability exists in the URL_decode functionality of Sealevel Systems, Inc. SeaConnect 370W v1.3.34. A specially-crafted MQTT payload can lead to an out-of-bounds write. An attacker can perform a man-in-the-middle attack to trigger this vulnerability.
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- partial
- Assessed
- 18 mo ago
Exploit prediction
0.70% chance of exploitation in the next 30 days, higher than 53% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- talosintelligence.com https://talosintelligence.com/vulnerability_reports/TALOS-2021-1397 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.0 | 3.7 | CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N |
| NVD | 3.1 | 5.9 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N |
| NVD | 2.0 | 4.3 | AV:N/AC:M/Au:N/C:N/I:P/A:N |
Affected products
- n/a Sealevel
Classification
- Weakness
-
- CWE-787 Out-of-bounds Write
References
-
talosintelligence.com
/vulnerability_reports/TALOS-2021-1397
exploit, technical-description, third-party-advisory
-
talosintelligence.com
/vulnerability_reports/TALOS-2021-1406
not-applicable, third-party-advisory
Sources
- CVE List CVE-2021-21971
- NVD CVE-2021-21971
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