synced 15 MIN AGO
01 Record

CVE-2021-3716

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

UnratedPUBLISHEDCNA: redhat
CNA base scoreUnratedNo CNA CVSS vector
View raw JSON

02 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

03 Exploitation and scoring

Exploitation
Not assessed. CISA has not published an exploitation assessment for this record, and it is not in the KEV catalog. That is an absence of assessment, not a finding of no risk.
SSVC decision
Not assessed by CISA
EPSS probability
0.58% probability of exploitation activity in the next 30 days.
EPSS percentile
Equal to or higher than the score of 47.6% of scored records. A rank, not a probability.
NVD base score
3.1 (CVSS v3.x), scored by the NVD independently of the CNA.
NVD CVSS vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L
NVD analysis status
Modified. NVD last modified this record on 2026-06-17.
Red Hat severity
Low. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published
2022-03-02 22:19Z4 YR AGO
Last updated
2024-08-03 17:01Z2 YR AGO
Reserved
2021-08-18
Assigning CNA
redhat
Record state
PUBLISHED
Severity
Not rated by the issuing CNA
CNA CVSS vector
Not published by the issuing CNA
Weaknesses
  • CWE-924Improper Enforcement of Message Integrity During Transmission in a Communication ChannelBase
Data version
5.1
Document digest
35ee65a251bf762592f7311851bef3d15424b2fb118d31990975bf494acbac25

05 Affected products

VendorProductVersionsPlatforms
n/anbdkitAffects nbdkit v1.12 through v1.26.4 | Fixedin nbdkit v1.26.5—

06 References

07 Fixed in

AlmaLinux 8

  • SLOF
    Fixed in 20210217-1.module_el8.6.0+2880+7d9e3703
  • hivex
    Fixed in 1.3.18-23.module_el8.6.0+2880+7d9e3703
  • hivex-devel
    Fixed in 1.3.18-23.module_el8.6.0+2880+7d9e3703
  • libguestfs
    Fixed in 1:1.44.0-5.module_el8.6.0+2880+7d9e3703.alma
  • libguestfs-appliance
    Fixed in 1:1.44.0-5.module_el8.6.0+2880+7d9e3703.alma
  • libguestfs-bash-completion
    Fixed in 1:1.44.0-5.module_el8.6.0+2880+7d9e3703.alma
  • libguestfs-devel
    Fixed in 1:1.44.0-5.module_el8.6.0+2880+7d9e3703.alma
  • libguestfs-gfs2
    Fixed in 1:1.44.0-5.module_el8.6.0+2880+7d9e3703.alma
  • libguestfs-gobject
    Fixed in 1:1.44.0-5.module_el8.6.0+2880+7d9e3703.alma
  • libguestfs-gobject-devel
    Fixed in 1:1.44.0-5.module_el8.6.0+2880+7d9e3703.alma
  • libguestfs-inspect-icons
    Fixed in 1:1.44.0-5.module_el8.6.0+2880+7d9e3703.alma
  • libguestfs-java
    Fixed in 1:1.44.0-5.module_el8.6.0+2880+7d9e3703.alma
  • libguestfs-java-devel
    Fixed in 1:1.44.0-5.module_el8.6.0+2880+7d9e3703.alma
  • libguestfs-javadoc
    Fixed in 1:1.44.0-5.module_el8.6.0+2880+7d9e3703.alma
  • libguestfs-man-pages-ja
    Fixed in 1:1.44.0-5.module_el8.6.0+2880+7d9e3703.alma
  • libguestfs-man-pages-uk
    Fixed in 1:1.44.0-5.module_el8.6.0+2880+7d9e3703.alma
  • libguestfs-rescue
    Fixed in 1:1.44.0-5.module_el8.6.0+2880+7d9e3703.alma
  • libguestfs-rsync
    Fixed in 1:1.44.0-5.module_el8.6.0+2880+7d9e3703.alma
  • libguestfs-tools
    Fixed in 1:1.44.0-5.module_el8.6.0+2880+7d9e3703.alma
  • libguestfs-tools-c
    Fixed in 1:1.44.0-5.module_el8.6.0+2880+7d9e3703.alma
  • libguestfs-winsupport
    Fixed in 8.6-1.module_el8.6.0+2880+7d9e3703
  • libguestfs-xfs
    Fixed in 1:1.44.0-5.module_el8.6.0+2880+7d9e3703.alma
  • libiscsi
    Fixed in 1.18.0-8.module_el8.6.0+2880+7d9e3703
  • libiscsi-devel
    Fixed in 1.18.0-8.module_el8.6.0+2880+7d9e3703
  • libiscsi-utils
    Fixed in 1.18.0-8.module_el8.6.0+2880+7d9e3703
  • libnbd
    Fixed in 1.6.0-5.module_el8.6.0+2880+7d9e3703
  • libnbd-bash-completion
    Fixed in 1.6.0-5.module_el8.6.0+2880+7d9e3703
  • libnbd-devel
    Fixed in 1.6.0-5.module_el8.6.0+2880+7d9e3703
  • libtpms
    Fixed in 0.9.1-0.20211126git1ff6fe1f43.module_el8.6.0+2880+7d9e3703
  • libtpms-devel
    Fixed in 0.9.1-0.20211126git1ff6fe1f43.module_el8.6.0+2880+7d9e3703
  • libvirt
    Fixed in 8.0.0-5.module_el8.6.0+2880+7d9e3703
  • libvirt-client
    Fixed in 8.0.0-5.module_el8.6.0+2880+7d9e3703
  • libvirt-daemon
    Fixed in 8.0.0-5.module_el8.6.0+2880+7d9e3703
  • libvirt-daemon-config-network
    Fixed in 8.0.0-5.module_el8.6.0+2880+7d9e3703
  • libvirt-daemon-config-nwfilter
    Fixed in 8.0.0-5.module_el8.6.0+2880+7d9e3703
  • libvirt-daemon-driver-interface
    Fixed in 8.0.0-5.module_el8.6.0+2880+7d9e3703
  • libvirt-daemon-driver-network
    Fixed in 8.0.0-5.module_el8.6.0+2880+7d9e3703
  • libvirt-daemon-driver-nodedev
    Fixed in 8.0.0-5.module_el8.6.0+2880+7d9e3703
  • libvirt-daemon-driver-nwfilter
    Fixed in 8.0.0-5.module_el8.6.0+2880+7d9e3703
  • libvirt-daemon-driver-qemu
    Fixed in 8.0.0-5.module_el8.6.0+2880+7d9e3703

90 further packages in AlmaLinux 8 not shown (first 40 listed).

Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

CloudLinux 8

  • SLOF
    Fixed in 20210217-1.module_el8.6.0+2880+7d9e3703
  • hivex
    Fixed in 1.3.18-23.module_el8.6.0+2880+7d9e3703
  • hivex-devel
    Fixed in 1.3.18-23.module_el8.6.0+2880+7d9e3703
  • libguestfs
    Fixed in 1:1.44.0-5.module_el8.6.0+2880+7d9e3703.alma
  • libguestfs-appliance
    Fixed in 1:1.44.0-5.module_el8.6.0+2880+7d9e3703.alma
  • libguestfs-bash-completion
    Fixed in 1:1.44.0-5.module_el8.6.0+2880+7d9e3703.alma
  • libguestfs-devel
    Fixed in 1:1.44.0-5.module_el8.6.0+2880+7d9e3703.alma
  • libguestfs-gfs2
    Fixed in 1:1.44.0-5.module_el8.6.0+2880+7d9e3703.alma
  • libguestfs-gobject
    Fixed in 1:1.44.0-5.module_el8.6.0+2880+7d9e3703.alma
  • libguestfs-gobject-devel
    Fixed in 1:1.44.0-5.module_el8.6.0+2880+7d9e3703.alma
  • libguestfs-inspect-icons
    Fixed in 1:1.44.0-5.module_el8.6.0+2880+7d9e3703.alma
  • libguestfs-java
    Fixed in 1:1.44.0-5.module_el8.6.0+2880+7d9e3703.alma
  • libguestfs-java-devel
    Fixed in 1:1.44.0-5.module_el8.6.0+2880+7d9e3703.alma
  • libguestfs-javadoc
    Fixed in 1:1.44.0-5.module_el8.6.0+2880+7d9e3703.alma
  • libguestfs-man-pages-ja
    Fixed in 1:1.44.0-5.module_el8.6.0+2880+7d9e3703.alma
  • libguestfs-man-pages-uk
    Fixed in 1:1.44.0-5.module_el8.6.0+2880+7d9e3703.alma
  • libguestfs-rescue
    Fixed in 1:1.44.0-5.module_el8.6.0+2880+7d9e3703.alma
  • libguestfs-rsync
    Fixed in 1:1.44.0-5.module_el8.6.0+2880+7d9e3703.alma
  • libguestfs-tools
    Fixed in 1:1.44.0-5.module_el8.6.0+2880+7d9e3703.alma
  • libguestfs-tools-c
    Fixed in 1:1.44.0-5.module_el8.6.0+2880+7d9e3703.alma
  • libguestfs-winsupport
    Fixed in 8.6-1.module_el8.6.0+2880+7d9e3703
  • libguestfs-xfs
    Fixed in 1:1.44.0-5.module_el8.6.0+2880+7d9e3703.alma
  • libiscsi
    Fixed in 1.18.0-8.module_el8.6.0+2880+7d9e3703
  • libiscsi-devel
    Fixed in 1.18.0-8.module_el8.6.0+2880+7d9e3703
  • libiscsi-utils
    Fixed in 1.18.0-8.module_el8.6.0+2880+7d9e3703
  • libnbd
    Fixed in 1.6.0-5.module_el8.6.0+2880+7d9e3703
  • libnbd-bash-completion
    Fixed in 1.6.0-5.module_el8.6.0+2880+7d9e3703
  • libnbd-devel
    Fixed in 1.6.0-5.module_el8.6.0+2880+7d9e3703
  • libtpms
    Fixed in 0.9.1-0.20211126git1ff6fe1f43.module_el8.6.0+2880+7d9e3703
  • libtpms-devel
    Fixed in 0.9.1-0.20211126git1ff6fe1f43.module_el8.6.0+2880+7d9e3703
  • libvirt
    Fixed in 8.0.0-5.module_el8.6.0+2880+7d9e3703
  • libvirt-client
    Fixed in 8.0.0-5.module_el8.6.0+2880+7d9e3703
  • libvirt-daemon
    Fixed in 8.0.0-5.module_el8.6.0+2880+7d9e3703
  • libvirt-daemon-config-network
    Fixed in 8.0.0-5.module_el8.6.0+2880+7d9e3703
  • libvirt-daemon-config-nwfilter
    Fixed in 8.0.0-5.module_el8.6.0+2880+7d9e3703
  • libvirt-daemon-driver-interface
    Fixed in 8.0.0-5.module_el8.6.0+2880+7d9e3703
  • libvirt-daemon-driver-network
    Fixed in 8.0.0-5.module_el8.6.0+2880+7d9e3703
  • libvirt-daemon-driver-nodedev
    Fixed in 8.0.0-5.module_el8.6.0+2880+7d9e3703
  • libvirt-daemon-driver-nwfilter
    Fixed in 8.0.0-5.module_el8.6.0+2880+7d9e3703
  • libvirt-daemon-driver-qemu
    Fixed in 8.0.0-5.module_el8.6.0+2880+7d9e3703

90 further packages in CloudLinux 8 not shown (first 40 listed).

Derived from AlmaLinux 8. Partial coverage: only packages taken from AlmaLinux 8 are listed.

Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

Debian 12

  • nbdkit
    Fixed in 1.26.5-1

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 13

  • nbdkit
    Fixed in 1.26.5-1

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 14

  • nbdkit
    Fixed in 1.26.5-1

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 16.04 LTS

  • nbdkit
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 20.04 LTS

  • nbdkit
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 22.04 LTS

  • nbdkit
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 24.04 LTS

  • nbdkit
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 25.10

  • nbdkit
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 26.04 LTS

  • nbdkit
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 26.10

  • nbdkit
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.