CVE-2021-3716

LOW
Published Mar 2, 20224y ago · Modified Jun 17, 20262w ago
3.1 CVSS 3.1
Low
Find Similar
Published Mar 2, 2022 4y ago
Last Modified Jun 17, 2026 2w ago

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.

CVSS Details

Base Score
3.1
Exploitability
1.6
Impact
1.4
Vector string
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L
Attack Vector Network
Attack Complexity High
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability Low

Threat Intelligence

No active exploitation signals — not in CISA KEV and no EPSS score yet.

Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-924

Affected Products 5

VendorProductVersionRange
nbdkit_projectnbdkit*≥1.11.8  –  <1.24.6
nbdkit_projectnbdkit*≥1.25.1  –  <1.26.5
nbdkit_projectnbdkit*≥1.27.1  –  <1.27.6
redhatenterprise_linux8.0any
redhatenterprise_linux8.0any

References 5

  • bugzilla.redhat.com https://bugzilla.redhat.com/show_bug.cgi?id=1994695
    Issue TrackingPatchThird Party Advisory
  • gitlab.com https://gitlab.com/nbdkit/nbdkit/-/commit/09a13dafb7bb3a38ab52eb5501cba786365ba7fd
    PatchThird Party Advisory
  • gitlab.com https://gitlab.com/nbdkit/nbdkit/-/commit/6c5faac6a37077cf2366388a80862bb00616d0d8
    PatchThird Party Advisory
  • listman.redhat.com https://listman.redhat.com/archives/libguestfs/2021-August/msg00083.html
    Broken Link
  • openwall.com https://www.openwall.com/lists/oss-security/2021/08/18/2
    Mailing ListThird Party Advisory

Remediation

  • bugzilla.redhat.com https://bugzilla.redhat.com/show_bug.cgi?id=1994695
    Issue TrackingPatchThird Party Advisory
  • gitlab.com https://gitlab.com/nbdkit/nbdkit/-/commit/09a13dafb7bb3a38ab52eb5501cba786365ba7fd
    PatchThird Party Advisory
  • gitlab.com https://gitlab.com/nbdkit/nbdkit/-/commit/6c5faac6a37077cf2366388a80862bb00616d0d8
    PatchThird Party Advisory