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CVE-2021-3716

LOW
3.1
CVSS Score
Published: March 2, 2022 at 10:19 PM UTC
Updated: June 17, 2026 at 04:05 AM UTC
2 products affected across 2 vendorsEnterprise LinuxNbdkit

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Severity
LOW3.1
Exploit prediction
EPSS 0.6%

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Nbdkit· Nbdkit Project
95%
v ≤ 1.26.41.11.8 ≤ v < 1.24.61.25.1 ≤ v < 1.26.51.27.1 ≤ v < 1.27.6
Affected range stops below 1.24.6, so it looks safe — our inference, not a vendor statement
Affected range stops below 1.26.5, so it looks safe — our inference, not a vendor statement
Affected range stops below 1.27.6, so it looks safe — our inference, not a vendor statement
Enterprise Linux· Red Hatrpm
95%
8.0

References (5)

x_refsource_MISCIssue TrackingPatchThird Party Advisory
Source: [email protected]
https://bugzilla.redhat.com/show_bug.cgi?id=1994695
x_refsource_MISCPatchThird Party Advisory
Source: [email protected]
https://gitlab.com/nbdkit/nbdkit/-/commit/09a13dafb7bb3a38ab52eb5501cba786365ba7fd
x_refsource_MISCPatchThird Party Advisory
Source: [email protected]
https://gitlab.com/nbdkit/nbdkit/-/commit/6c5faac6a37077cf2366388a80862bb00616d0d8
x_refsource_MISCBroken Link
Source: [email protected]
https://listman.redhat.com/archives/libguestfs/2021-August/msg00083.html
x_refsource_MISCMailing ListThird Party Advisory
Source: [email protected]
https://www.openwall.com/lists/oss-security/2021/08/18/2

CVSS

3.1LOW[email protected]
Attack Vector
NETWORK
Complexity
HIGH
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
LOW
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-924NVD-CWE-Other

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