CVE-2021-3716
LOWDescription
A flaw was found in nbdkit due to to improperly caching plaintext state across the STARTTLS encryption boundary. A MitM attacker could use this flaw to inject a plaintext NBD_OPT_STRUCTURED_REPLY before proxying everything else a client sends to the server, potentially leading the client to terminate the NBD session. The highest threat from this vulnerability is to system availability.
How to fix
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L
Exploit Intelligence
Moderate risk: more likely to be exploited than 45% of all known CVEs.
References
Related Vulnerabilities
Other CWE-924 vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2024-3596 | Critical | 9.0 | 15% | - | Fix |
| CVE-2018-14526 | Medium | 6.5 | 1.5% | - | Fix |
| CVE-2021-21390 | Medium | 6.5 | 0.9% | - | Fix |
| CVE-2022-3166 | High | 7.5 | 0.7% | - | - |
| CVE-2021-34793 | High | 8.6 | 0.6% | - | Fix |
| CVE-2024-43450 | High | 7.5 | 0.6% | - | Fix |
Common questions
How do I fix CVE-2021-3716?
Upgrade nbdkit on debian 12 to 1.26.5-1 or later.
Is CVE-2021-3716 being actively exploited?
Not that we know of. CVE-2021-3716 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.58% is the estimated probability that it will be exploited in the next 30 days. That is higher than 45% of all scored CVEs.
How severe is CVE-2021-3716?
CVE-2021-3716 has a CVSS v3 base score of 3.1, rated low. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2021-3716 affect?
Published advisories record a fix for nbdkit (Debian). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
Embed a live status badge for CVE-2021-3716
Markdown
[](https://tridentstack.com/cve/CVE-2021-3716)HTML
<a href="https://tridentstack.com/cve/CVE-2021-3716"><img src="https://tridentstack.com/cve/badge/CVE-2021-3716.svg" alt="CVE-2021-3716"></a>Find and fix vulnerabilities across your fleet
TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.
This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.