CVE-2021-20286
A flaw was found in libnbd 1.7.3. An assertion failure in nbd_unlocked_opt_go in ilb/opt.c may...
A flaw was found in libnbd 1.7.3. An assertion failure in nbd_unlocked_opt_go in ilb/opt.c may lead to denial of service.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- High
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- Low
Exploit likelihood
What each source reports
NVD Score used
A flaw was found in libnbd 1.7.3. An assertion failure in nbd_unlocked_opt_go in ilb/opt.c may lead to denial of service.
- Record
CVE-2021-20286- CVSS 3.1
- 2.7 Low
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L - CVSS 2.0
- 4.0 Medium
AV:N/AC:L/Au:S/C:N/I:N/A:P - Weakness
- CWE-617
- Updated
- 2026-11-02
CVE List No score
A flaw was found in libnbd 1.7.3. An assertion failure in nbd_unlocked_opt_go in ilb/opt.c may lead to denial of service.
- Record
CVE-2021-20286- Weakness
- CWE-617
- Updated
- 2026-11-02
EUVDEUVD-2021-7714 No score
A flaw was found in libnbd 1.7.3. An assertion failure in nbd_unlocked_opt_go in ilb/opt.c may lead to denial of service.
- Record
EUVD-2021-7714- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-r4rf-vx7w-8692 No score
A flaw was found in libnbd 1.7.3. An assertion failure in nbd_unlocked_opt_go in ilb/opt.c may...
A flaw was found in libnbd 1.7.3. An assertion failure in nbd_unlocked_opt_go in ilb/opt.c may lead to denial of service.
- Record
GHSA-r4rf-vx7w-8692- Weakness
- CWE-617
- Updated
- 2026-11-02
OSVALPINE-CVE-2021-20286
A flaw was found in libnbd 1.7.3. An assertion failure in nbd_unlocked_opt_go in ilb/opt.c may lead to denial of service.
- Record
ALPINE-CVE-2021-20286- CVSS 3.1
- 2.7 Low
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L - Updated
- 2026-11-03
OSVAZL-7265
CVE-2021-20286 affecting package libnbd for versions less than 1.12.1-1
A flaw was found in libnbd 1.7.3. An assertion failure in nbd_unlocked_opt_go in ilb/opt.c may lead to denial of service.
- Record
AZL-7265- CVSS 3.1
- 2.7 Low
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L - Updated
- 2026-11-02
Show 6 moreShow less
OSV
A flaw was found in libnbd 1.7.3. An assertion failure in nbd_unlocked_opt_go in ilb/opt.c may lead to denial of service.
- Record
CVE-2021-20286- CVSS 3.1
- 2.7 Low
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L - Updated
- 2026-11-02
OSVDEBIAN-CVE-2021-20286
A flaw was found in libnbd 1.7.3. An assertion failure in nbd_unlocked_opt_go in ilb/opt.c may lead to denial of service.
- Record
DEBIAN-CVE-2021-20286- CVSS 3.1
- 2.7 Low
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L - Updated
- 2026-11-02
OSVUBUNTU-CVE-2021-20286
A flaw was found in libnbd 1.7.3. An assertion failure in nbd_unlocked_opt_go in ilb/opt.c may lead to denial of service.
- Record
UBUNTU-CVE-2021-20286- CVSS 3.1
- 2.7 Low
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L - Updated
- 2026-11-02
OSVopenSUSE-SU-2021:2274-1 No score
Security update for kubevirt
This update for kubevirt fixes the following issues:
General:
- Updated kubevirt to version 0.40.0
- Fixed an issue when calling
virsh-domcapabilities - Fixed the the wrong registry path for containers.
Security fixes:
- CVE-2021-20286: A flaw was found in libnbd 1.7.3. An assertion failure in nbd_unlocked_opt_go in ilb/opt.c may lead to denial of service.
- Record
openSUSE-SU-2021:2274-1- Updated
- 2026-11-02
OSVopenSUSE-SU-2024:10961-1 No score
libnbd-1.9.3-1.2 on GA media
These are all security issues fixed in the libnbd-1.9.3-1.2 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2024:10961-1- Updated
- 2026-11-02
OSVSUSE-SU-2021:2274-1 No score
Security update for kubevirt
This update for kubevirt fixes the following issues:
General:
- Updated kubevirt to version 0.40.0
- Fixed an issue when calling
virsh-domcapabilities - Fixed the the wrong registry path for containers.
Security fixes:
- CVE-2021-20286: A flaw was found in libnbd 1.7.3. An assertion failure in nbd_unlocked_opt_go in ilb/opt.c may lead to denial of service.
- Record
SUSE-SU-2021:2274-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
libnbdAlpine:v3.20 |
before 1.10.5-r0 | 1.10.5-r0 |
libnbdAlpine:v3.21 |
before 1.10.5-r0 | 1.10.5-r0 |
libnbdAlpine:v3.22 |
before 1.10.5-r0 | 1.10.5-r0 |
libnbdAlpine:v3.23 |
before 1.10.5-r0 | 1.10.5-r0 |
libnbdAlpine:v3.24 |
before 1.10.5-r0 | 1.10.5-r0 |
libnbdAzure Linux:2 |
before 1.12.1-1 | 1.12.1-1 |
libnbdDebian:12 |
before 1.6.2-1 | 1.6.2-1 |
libnbdDebian:13 |
before 1.6.2-1 | 1.6.2-1 |
libnbdDebian:14 |
before 1.6.2-1 | 1.6.2-1 |
containerized-data-importerSUSE:Linux Enterprise Module for Containers 15 SP2 |
before 1.30.0-5.3.2 | 1.30.0-5.3.2 |
Show 5 moreShow less
| Package | Affected | Fixed |
|---|---|---|
kubevirtSUSE:Linux Enterprise Module for Containers 15 SP2 |
before 0.40.0-5.11.2 | 0.40.0-5.11.2 |
kubevirtSUSE:Linux Enterprise Module for Containers 15 SP3 |
before 0.40.0-5.11.2 | 0.40.0-5.11.2 |
libnbdUbuntu:20.04:LTS |
All versions, plus listed versions 1.0.3-11.2.1-21.2.2-1ubuntu2 |
None known |
kubevirtopenSUSE:Leap 15.3 |
before 0.40.0-5.11.2 | 0.40.0-5.11.2 |
libnbdopenSUSE:Tumbleweed |
before 1.9.3-1.2 | 1.9.3-1.2 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, aliases, references | OSV | |
| aliases, products | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-20286 is a low vulnerability (CVSS 2.7) in Red Hat Libnbd, published March 15, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.14%, the 66th percentile. Fixed in libnbd 1.10.5-r0.