CVE-2021-20201
A flaw was found in spice in versions before 0.14.92. A DoS tool might make it easier for remote...
A flaw was found in spice in versions before 0.14.92. A DoS tool might make it easier for remote attackers to cause a denial of service (CPU consumption) by performing many renegotiations within a single connection.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- 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 spice in versions before 0.14.92. A DoS tool might make it easier for remote attackers to cause a denial of service (CPU consumption) by performing many renegotiations within a single connection.
- Record
CVE-2021-20201- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:N/I:N/A:P - Weakness
- CWE-400
- Updated
- 2026-11-02
CVE List No score
A flaw was found in spice in versions before 0.14.92. A DoS tool might make it easier for remote attackers to cause a denial of service (CPU consumption) by performing many renegotiations within a single connection.
- Record
CVE-2021-20201- Weakness
- CWE-400
- Updated
- 2026-11-02
EUVDEUVD-2021-7646 No score
A flaw was found in spice in versions before 0.14.92. A DoS tool might make it easier for remote attackers to cause a denial of service (CPU consumption) by performing many renegotiations within a single connection.
- Record
EUVD-2021-7646- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-f3pm-m5m9-45gw
A flaw was found in spice in versions before 0.14.92. A DoS tool might make it easier for remote...
A flaw was found in spice in versions before 0.14.92. A DoS tool might make it easier for remote attackers to cause a denial of service (CPU consumption) by performing many renegotiations within a single connection.
- Record
GHSA-f3pm-m5m9-45gw- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Weakness
- CWE-400
- Updated
- 2026-11-02
OSVALPINE-CVE-2021-20201
A flaw was found in spice in versions before 0.14.92. A DoS tool might make it easier for remote attackers to cause a denial of service (CPU consumption) by performing many renegotiations within a single connection.
- Record
ALPINE-CVE-2021-20201- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Updated
- 2026-11-02
OSVBELL-CVE-2021-20201
CVE-2021-20201 does not affect BellSoft software
- Record
BELL-CVE-2021-20201- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Updated
- 2026-11-02
Show 20 moreShow less
OSV
A flaw was found in spice in versions before 0.14.92. A DoS tool might make it easier for remote attackers to cause a denial of service (CPU consumption) by performing many renegotiations within a single connection.
- Record
CVE-2021-20201- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Updated
- 2026-11-02
OSVDEBIAN-CVE-2021-20201
A flaw was found in spice in versions before 0.14.92. A DoS tool might make it easier for remote attackers to cause a denial of service (CPU consumption) by performing many renegotiations within a single connection.
- Record
DEBIAN-CVE-2021-20201- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Updated
- 2026-11-02
OSVOESA-2021-1233
spice security update
The SPICE package provides the SPICE server library and client. These components are used to provide access to a remote machine's display and devices.
Security Fix(es):
A flaw was found in spice in versions before 0.14.92. A DoS tool might make it easier for remote attackers to cause a denial of service (CPU consumption) by performing many renegotiations within a single connection.(CVE-2021-20201)
- Record
OESA-2021-1233- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVRHSA-2021:1924
Red Hat Security Advisory: spice security update
- Record
RHSA-2021:1924- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Updated
- 2026-11-02
OSVRLSA-2021:1924
Low: spice security update
The Simple Protocol for Independent Computing Environments (SPICE) is a remote display system built for virtual environments which allows the user to view a computing 'desktop' environment not only on the machine where it is running, but from anywhere on the Internet and from a wide variety of machine architectures.
Security Fix(es):
- spice: Client initiated renegotiation denial of service (CVE-2021-20201)
For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.
Additional Changes:
For detailed information on changes in this release, see the Rocky Linux 8.4 Release Notes linked from the References section.
- Record
RLSA-2021:1924- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Updated
- 2026-11-02
OSVUBUNTU-CVE-2021-20201
A flaw was found in spice in versions before 0.14.92. A DoS tool might make it easier for remote attackers to cause a denial of service (CPU consumption) by performing many renegotiations within a single connection.
- Record
UBUNTU-CVE-2021-20201- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Updated
- 2026-11-02
OSVALSA-2021:1924 No score
Low: spice security update
The Simple Protocol for Independent Computing Environments (SPICE) is a remote display system built for virtual environments which allows the user to view a computing 'desktop' environment not only on the machine where it is running, but from anywhere on the Internet and from a wide variety of machine architectures.
Security Fix(es):
- spice: Client initiated renegotiation denial of service (CVE-2021-20201)
For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.
Additional Changes:
For detailed information on changes in this release, see the AlmaLinux Release Notes linked from the References section.
- Record
ALSA-2021:1924- Updated
- 2026-11-02
OSVCLSA-2026-1778489013 No score
spice: Fix of CVE-2021-20201
- CVE-2021-20201: fix DoS via uncontrolled TLS renegotiation by disabling client-initiated renegotiation
- Record
CLSA-2026-1778489013- Updated
- 2026-11-02
OSVMGASA-2021-0405 No score
Updated spice packages fix security vulnerability
Updated spice packages fix security vulnerability:
A flaw was found in spice in versions before 0.14.92. A DoS tool might make it easier for remote attackers to cause a denial of service (CPU consumption) by performing many renegotiations within a single connection (CVE-2021-20201).
- Record
MGASA-2021-0405- Updated
- 2026-11-02
OSVopenSUSE-SU-2021:0874-1 No score
Security update for spice
This update for spice fixes the following issues:
- CVE-2021-20201: client initiated renegotiation causing denial of service (bsc#1181686)
This update was imported from the SUSE:SLE-15-SP2:Update update project.
- Record
openSUSE-SU-2021:0874-1- Updated
- 2026-11-02
OSVopenSUSE-SU-2024:12406-1 No score
libspice-client-glib-2_0-8-0.41-3.1 on GA media
These are all security issues fixed in the libspice-client-glib-2_0-8-0.41-3.1 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2024:12406-1- Updated
- 2026-11-02
OSVopenSUSE-SU-2024:13045-1 No score
libspice-server-devel-0.15.2-2.1 on GA media
These are all security issues fixed in the libspice-server-devel-0.15.2-2.1 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2024:13045-1- Updated
- 2026-11-02
OSVSUSE-SU-2021:14744-1 No score
Security update for spice
This update for spice fixes the following issues:
- CVE-2021-20201: client initiated renegotiation causing denial of service (bsc#1181686)
- CVE-2020-14355: Fixed multiple buffer overflow vulnerabilities in QUIC decoding code (bsc#1177158)
- CVE-2016-2150: Fixed a guest escape using crafted primary surface parameters (bsc#982386)
- Record
SUSE-SU-2021:14744-1- Updated
- 2026-11-02
OSVSUSE-SU-2021:1901-1 No score
Security update for spice
This update for spice fixes the following issues:
- CVE-2021-20201: client initiated renegotiation causing denial of service (bsc#1181686)
- CVE-2020-14355: Fixed multiple buffer overflow vulnerabilities in QUIC decoding code (bsc#1177158)
- Record
SUSE-SU-2021:1901-1- Updated
- 2026-11-02
OSVSUSE-SU-2021:1902-1 No score
Security update for spice
This update for spice fixes the following issues:
- CVE-2021-20201: client initiated renegotiation causing denial of service (bsc#1181686)
- CVE-2020-14355: Fixed multiple buffer overflow vulnerabilities in QUIC decoding code (bsc#1177158)
- Record
SUSE-SU-2021:1902-1- Updated
- 2026-11-02
OSVSUSE-SU-2021:1906-1 No score
Security update for spice
This update for spice fixes the following issues:
- CVE-2021-20201: client initiated renegotiation causing denial of service (bsc#1181686)
- Record
SUSE-SU-2021:1906-1- Updated
- 2026-11-02
OSVSUSE-SU-2021:1927-1 No score
Security update for spice
This update for spice fixes the following issues:
- CVE-2021-20201: client initiated renegotiation causing denial of service (bsc#1181686)
- Record
SUSE-SU-2021:1927-1- Updated
- 2026-11-02
OSVSUSE-SU-2021:1956-1 No score
Security update for spice
This update for spice fixes the following issues:
- CVE-2021-20201: client initiated renegotiation causing denial of service (bsc#1181686)
- CVE-2020-14355: Fixed multiple buffer overflow vulnerabilities in QUIC decoding code (bsc#1177158)
- Record
SUSE-SU-2021:1956-1- Updated
- 2026-11-02
OSVSUSE-SU-2022:2881-1 No score
Security update for spice
This update for spice fixes the following issues:
- CVE-2021-20201: Fixed an issue which could allow clients to cause a denial of service by repeatedly renegotiating a connection (bsc#1181686).
- Record
SUSE-SU-2022:2881-1- Updated
- 2026-11-02
OSVSUSE-SU-2022:2881-2 No score
Security update for spice
This update for spice fixes the following issues:
- CVE-2021-20201: Fixed an issue which could allow clients to cause a denial of service by repeatedly renegotiating a connection (bsc#1181686).
- Record
SUSE-SU-2022:2881-2- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
spiceAlpine:v3.10 |
before 0.14.2-r1 | 0.14.2-r1 |
spiceAlpine:v3.11 |
before 0.14.2-r2 | 0.14.2-r2 |
spiceAlpine:v3.12 |
before 0.14.3-r1 | 0.14.3-r1 |
spiceAlpine:v3.13 |
before 0.14.3-r1 | 0.14.3-r1 |
spiceAlpine:v3.14 |
before 0.14.3-r1 | 0.14.3-r1 |
spiceAlpine:v3.15 |
before 0.14.3-r1 | 0.14.3-r1 |
spiceAlpine:v3.16 |
before 0.14.3-r1 | 0.14.3-r1 |
spiceAlpine:v3.17 |
before 0.14.3-r1 | 0.14.3-r1 |
spiceAlpine:v3.18 |
before 0.14.3-r1 | 0.14.3-r1 |
spiceAlpine:v3.19 |
before 0.14.3-r1 | 0.14.3-r1 |
Show 63 moreShow less
| Package | Affected | Fixed |
|---|---|---|
spiceAlpine:v3.20 |
before 0.14.3-r1 | 0.14.3-r1 |
spiceAlpine:v3.21 |
before 0.14.3-r1 | 0.14.3-r1 |
spiceAlpine:v3.22 |
before 0.14.3-r1 | 0.14.3-r1 |
spiceAlpine:v3.23 |
before 0.14.3-r1 | 0.14.3-r1 |
spiceAlpine:v3.24 |
before 0.14.3-r1 | 0.14.3-r1 |
spice-serverAlmaLinux:8 |
before 0.14.3-4.el8 | 0.14.3-4.el8 |
spice-server-develAlmaLinux:8 |
before 0.14.3-4.el8 | 0.14.3-4.el8 |
spice-serverTuxCare:CentOS:7 |
before 0.14.0-9.el7_9.1.tuxcare.els1 | 0.14.0-9.el7_9.1.tuxcare.els1 |
spice-server-develTuxCare:CentOS:7 |
before 0.14.0-9.el7_9.1.tuxcare.els1 | 0.14.0-9.el7_9.1.tuxcare.els1 |
spiceDebian:12 |
before 0.14.3-2.1 | 0.14.3-2.1 |
spiceDebian:13 |
before 0.14.3-2.1 | 0.14.3-2.1 |
spiceDebian:14 |
before 0.14.3-2.1 | 0.14.3-2.1 |
spiceMageia:8 |
before 0.14.3-3.1.mga8 | 0.14.3-3.1.mga8 |
spiceopenEuler:20.03-LTS-SP1 |
before 0.14.3-3.oe1 | 0.14.3-3.oe1 |
spiceRed Hat:enterprise_linux:8::appstream |
before 0:0.14.3-4.el8 | 0:0.14.3-4.el8 |
spice-debugsourceRed Hat:enterprise_linux:8::appstream |
before 0:0.14.3-4.el8 | 0:0.14.3-4.el8 |
spice-serverRed Hat:enterprise_linux:8::appstream |
before 0:0.14.3-4.el8 | 0:0.14.3-4.el8 |
spice-server-debuginfoRed Hat:enterprise_linux:8::appstream |
before 0:0.14.3-4.el8 | 0:0.14.3-4.el8 |
spice-debugsourceRed Hat:enterprise_linux:8::crb |
before 0:0.14.3-4.el8 | 0:0.14.3-4.el8 |
spice-server-debuginfoRed Hat:enterprise_linux:8::crb |
before 0:0.14.3-4.el8 | 0:0.14.3-4.el8 |
spice-server-develRed Hat:enterprise_linux:8::crb |
before 0:0.14.3-4.el8 | 0:0.14.3-4.el8 |
spiceRocky Linux:8 |
before 0:0.14.3-4.el8 | 0:0.14.3-4.el8 |
spiceSUSE:Linux Enterprise Server 11 SP4-LTSS From an advisory covering 3 CVEs |
before 0.12.4-21.1 | 0.12.4-21.1 |
spiceSUSE:Linux Enterprise High Performance Computing 15-ESPOS From an advisory covering 2 CVEs |
before 0.14.0-4.9.1 | 0.14.0-4.9.1 |
spiceSUSE:Linux Enterprise High Performance Computing 15-LTSS From an advisory covering 2 CVEs |
before 0.14.0-4.9.1 | 0.14.0-4.9.1 |
spiceSUSE:Linux Enterprise Server 15-LTSS From an advisory covering 2 CVEs |
before 0.14.0-4.9.1 | 0.14.0-4.9.1 |
spiceSUSE:Linux Enterprise Server for SAP Applications 15 From an advisory covering 2 CVEs |
before 0.14.0-4.9.1 | 0.14.0-4.9.1 |
spiceSUSE:Linux Enterprise Server 12 SP2-BCL From an advisory covering 2 CVEs |
before 0.12.7-10.12.1 | 0.12.7-10.12.1 |
spiceSUSE:HPE Helion OpenStack 8 |
before 0.12.8-18.1 | 0.12.8-18.1 |
spiceSUSE:OpenStack Cloud 8 |
before 0.12.8-18.1 | 0.12.8-18.1 |
spiceSUSE:OpenStack Cloud 9 |
before 0.12.8-18.1 | 0.12.8-18.1 |
spiceSUSE:OpenStack Cloud Crowbar 8 |
before 0.12.8-18.1 | 0.12.8-18.1 |
spiceSUSE:OpenStack Cloud Crowbar 9 |
before 0.12.8-18.1 | 0.12.8-18.1 |
spiceSUSE:Linux Enterprise Server for SAP Applications 12 SP3 |
before 0.12.8-18.1 | 0.12.8-18.1 |
spiceSUSE:Linux Enterprise Server for SAP Applications 12 SP4 |
before 0.12.8-18.1 | 0.12.8-18.1 |
spiceSUSE:Linux Enterprise Software Development Kit 12 SP5 |
before 0.12.8-18.1 | 0.12.8-18.1 |
spiceSUSE:Linux Enterprise Server 12 SP3-LTSS |
before 0.12.8-18.1 | 0.12.8-18.1 |
spiceSUSE:Linux Enterprise Server 12 SP3-BCL |
before 0.12.8-18.1 | 0.12.8-18.1 |
spiceSUSE:Linux Enterprise Server 12 SP4-LTSS |
before 0.12.8-18.1 | 0.12.8-18.1 |
spiceSUSE:Linux Enterprise Server 12 SP5 |
before 0.12.8-18.1 | 0.12.8-18.1 |
spiceSUSE:Linux Enterprise Server for SAP Applications 12 SP5 |
before 0.12.8-18.1 | 0.12.8-18.1 |
spiceSUSE:Linux Enterprise Module for Server Applications 15 SP2 |
before 0.14.2-3.6.1 | 0.14.2-3.6.1 |
spiceSUSE:Linux Enterprise Micro 5.0 |
before 0.14.2-3.6.1 | 0.14.2-3.6.1 |
spiceSUSE:Linux Enterprise High Performance Computing 15 SP1-ESPOS From an advisory covering 2 CVEs |
before 0.14.1-4.3.1 | 0.14.1-4.3.1 |
spiceSUSE:Linux Enterprise High Performance Computing 15 SP1-LTSS From an advisory covering 2 CVEs |
before 0.14.1-4.3.1 | 0.14.1-4.3.1 |
spiceSUSE:Linux Enterprise Server 15 SP1-BCL From an advisory covering 2 CVEs |
before 0.14.1-4.3.1 | 0.14.1-4.3.1 |
spiceSUSE:Linux Enterprise Server 15 SP1-LTSS From an advisory covering 2 CVEs |
before 0.14.1-4.3.1 | 0.14.1-4.3.1 |
spiceSUSE:Linux Enterprise Server for SAP Applications 15 SP1 From an advisory covering 2 CVEs |
before 0.14.1-4.3.1 | 0.14.1-4.3.1 |
spiceSUSE:Manager Proxy 4.0 From an advisory covering 2 CVEs |
before 0.14.1-4.3.1 | 0.14.1-4.3.1 |
spiceSUSE:Manager Retail Branch Server 4.0 From an advisory covering 2 CVEs |
before 0.14.1-4.3.1 | 0.14.1-4.3.1 |
spiceSUSE:Manager Server 4.0 From an advisory covering 2 CVEs |
before 0.14.1-4.3.1 | 0.14.1-4.3.1 |
spiceSUSE:Enterprise Storage 6 From an advisory covering 2 CVEs |
before 0.14.1-4.3.1 | 0.14.1-4.3.1 |
spiceSUSE:Linux Enterprise Module for Server Applications 15 SP3 |
before 0.14.3-150300.3.3.1 | 0.14.3-150300.3.3.1 |
spiceSUSE:Linux Enterprise Micro 5.2 |
before 0.14.3-150300.3.3.1 | 0.14.3-150300.3.3.1 |
spiceopenSUSE:Leap 15.3 |
before 0.14.3-150300.3.3.1 | 0.14.3-150300.3.3.1 |
spiceopenSUSE:Leap Micro 5.2 |
before 0.14.3-150300.3.3.1 | 0.14.3-150300.3.3.1 |
spiceUbuntu:Pro:14.04:LTS |
All versions, plus listed versions 0.12.4-0nocelt10.12.4-0nocelt1.10.12.4-0nocelt1.1ubuntu10.12.4-0nocelt20.12.4-0nocelt2ubuntu1 Show 9 moreShow less0.12.4-0nocelt2ubuntu1.10.12.4-0nocelt2ubuntu1.20.12.4-0nocelt2ubuntu1.30.12.4-0nocelt2ubuntu1.40.12.4-0nocelt2ubuntu1.50.12.4-0nocelt2ubuntu1.60.12.4-0nocelt2ubuntu1.70.12.4-0nocelt2ubuntu1.80.12.4-0nocelt2ubuntu1.8+esm1 |
None known |
spiceUbuntu:16.04:LTS |
All versions, plus listed versions 0.12.5-1.1ubuntu20.12.6-40.12.6-4ubuntu0.10.12.6-4ubuntu0.20.12.6-4ubuntu0.30.12.6-4ubuntu0.40.12.6-4ubuntu0.5 |
None known |
spiceUbuntu:18.04:LTS |
All versions, plus listed versions 0.12.8-2.20.14.0-10.14.0-1ubuntu10.14.0-1ubuntu20.14.0-1ubuntu2.10.14.0-1ubuntu2.20.14.0-1ubuntu2.40.14.0-1ubuntu2.5 |
None known |
spiceUbuntu:20.04:LTS |
All versions, plus listed versions 0.14.2-0ubuntu20.14.2-4ubuntu10.14.2-4ubuntu20.14.2-4ubuntu30.14.2-4ubuntu3.1 |
None known |
spiceopenSUSE:Leap 15.2 |
before 0.14.2-lp152.2.6.1 | 0.14.2-lp152.2.6.1 |
spice-gtkopenSUSE:Tumbleweed |
before 0.41-3.1 | 0.41-3.1 |
spiceopenSUSE:Tumbleweed |
before 0.15.2-2.1 | 0.15.2-2.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| 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-2021-20201 is a medium vulnerability (CVSS 5.3) in Red Hat, Inc. Spice, published May 18, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 2.70%, the 86th percentile. Fixed in spice 0.14.2-r1.
References
bugzilla.redhat.com/show_bug.cgi?id=1921846
blog.qualys.com/product-tech/2011/10/31/tls-renegotiation-and-denial-of-service-attacks
security.gentoo.org/glsa/202208-10
nvd.nist.gov/vuln/detail/CVE-2021-20201
github.com/advisories/GHSA-f3pm-m5m9-45gw
security.alpinelinux.org/vuln/CVE-2021-20201
Show 32 moreShow less
errata.almalinux.org/8/ALSA-2021-1924.html
vulners.com/cve/CVE-2021-20201
docs.bell-sw.com/security/cves/CVE-2021-20201
errata.tuxcare.com/els_os/centos7els/CLSA-2026-1778489013.html
security-tracker.debian.org/tracker/CVE-2021-20201
advisories.mageia.org/MGASA-2021-0405.html
bugs.mageia.org/show_bug.cgi?id=28947
access.redhat.com/errata/RHSA-2021:1924
lists.opensuse.org/archives/list/[email protected]/thread/AINSWYQLD5FH4GUOEP5FWWA5CMFHTUDX
openeuler.org/en/security/safety-bulletin/detail.html?id=openEuler-SA-2021-1233
security.access.redhat.com/data/csaf/v2/advisories/2021/rhsa-2021_1924.json
cve.org/CVERecord?id=CVE-2021-20201
errata.rockylinux.org/RLSA-2021:1924
suse.com/support/update/announcement/2021/suse-su-202114744-1
bugzilla.suse.com/1177158
ubuntu.com/security/CVE-2021-20201