Low
nbdkit — security advisory
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.
- Products
- nbdkit
- Affected versions
- 1.1.10-1, 1.1.11-1, 1.1.11-1build1, 1.12.4-1, 1.12.4-1build1, 1.14.2-3, 1.16.1-2, 1.16.1-3, 1.16.1-3ubuntu1, 1.16.2-1ubuntu1, 1.16.2-1ubuntu2, 1.16.2-1ubuntu3, 1.24.1-2ubuntu1, 1.24.1-2ubuntu2, 1.24.1-2ubuntu3, 1.24.1-2ubuntu4, 1.34.4-1ubuntu1, 1.36.1-1ubuntu1, 1.36.2-1ubuntu1, 1.36.3-1ubuntu10, 1.36.3-1ubuntu2, 1.36.3-1ubuntu3, 1.36.3-1ubuntu9, 1.42.2-1ubuntu1, 1.42.3-1ubuntu1, 1.42.4-1ubuntu1, 1.42.6-1ubuntu1, 1.42.9-1ubuntu1, 1.42.9-1ubuntu2, 1.46.2-1ubuntu2, 1.46.2-4ubuntu1, 1.46.2-5ubuntu1, 1.46.2-7ubuntu1, 1.48.0-1ubuntu1, 1.48.0-1ubuntu2
- Fixed versions
- Not specified
- CVEs
- CVE-2021-3716
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 01:37 UTC · Revision 1
Source evidence
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.
osv:UBUNTU-CVE-2021-3716
nbdkit
Fixed versions: Not specified
nbdkit
Fixed versions: Not specified
nbdkit
Fixed versions: Not specified
nbdkit
Fixed versions: Not specified
nbdkit
Fixed versions: Not specified
nbdkit
Fixed versions: Not specified
nbdkit
Fixed versions: Not specified
Complete source record
{
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"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2021-3716",
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],
"modified": "2026-10-17T12:57:13.451999957Z",
"provider": "osv",
"upstream": [
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],
"references": [
"https://ubuntu.com/security/CVE-2021-3716",
"https://access.redhat.com/security/cve/CVE-2021-3716",
"https://listman.redhat.com/archives/libguestfs/2021-August/msg00077.html",
"https://www.cve.org/CVERecord?id=CVE-2021-3716"
]
},
"related_cves": [
{
"value": "CVE-2021-3716",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 356944,
"published_at": "2022-03-02T23:15:00+00:00"
}