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Fencer Vulns
medium 5.3

CVE-2021-20201 json

A flaw was found in spice in versions before 0.14.92.

published 2021-05-28 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-7646

cvss
5.3
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
2.5%
EPSS 2.5% chance of exploitation in 30 days, percentile 84%
public exploits
0
none known

Summary

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.

Patch / fix

  • spice_project spice 0.14.92
  • spice Debian 14, Debian 13, Debian 12 0.14.3-2.1

debian advisories DEBIAN-CVE-2021-20201

  • spice RHEL 8 0.14.3-4.el8
  • spice-server RHEL 8 0.14.3-4.el8

red hat advisories RHSA-2021:1924

  • spice SLE Module for Server Applications 15 SP3, SLE Micro 5.2, openSUSE Leap Micro 5.2 +1 more 0.14.3-150300.3.3.1
  • spice SLES for SAP 15 SP1, SLES 15 SP1-LTSS, SLES 15 SP1-BCL +6 more 0.14.1-4.3.1
  • spice SLE Module for Server Applications 15 SP2, SLE Micro 5.0 0.14.2-3.6.1
  • spice SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES for SAP 12 SP3 +10 more 0.12.8-18.1
  • spice SLES 12 SP2-BCL 0.12.7-10.12.1
  • spice SLES for SAP 15, SLES 15-LTSS, SLE High Performance Computing 15-LTSS +1 more 0.14.0-4.9.1
  • spice SLES 11 SP4-LTSS 0.12.4-21.1

suse advisories SUSE-SU-2022:2881-2SUSE-SU-2022:2881-1SUSE-SU-2021:1956-1SUSE-SU-2021:1927-1SUSE-SU-2021:1906-1SUSE-SU-2021:14744-1

  • spice-gtk openSUSE Tumbleweed 0.41-3.1
  • spice openSUSE Tumbleweed 0.15.2-2.1
  • spice openSUSE Leap 15.2 0.14.2-lp152.2.6.1

opensuse advisories openSUSE-SU-2024:12406-1openSUSE-SU-2024:13045-1openSUSE-SU-2021:0874-1

  • spice-server AlmaLinux 8 0.14.3-4.el8

almalinux advisories ALSA-2021:1924

  • spice Rocky Linux 8 0.14.3-4.el8

rocky linux advisories RLSA-2021:1924

  • spice Alpine 3.10 0.14.2-r1
  • spice Alpine 3.11 0.14.2-r2
  • spice Alpine 3.24, Alpine 3.23, Alpine 3.22 +10 more 0.14.3-r1

alpine advisories ALPINE-CVE-2021-20201

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • spice Arch Linux 0.15.0-1

arch linux advisories AVG-1239

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-20201 updated cvss 5.3

spice: Client initiated renegotiation denial of service

  • Red Hat Enterprise Linux 6 spice-server Red Hat Enterprise Linux 7 spice, spice-server
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 9 spice
    affected: no fix available
  • Red Hat CodeReady Linux Builder (v. 8) spice-debugsource 0.14.3-4.el8, spice-server-devel 0.14.3-4.el8, spice-server-debuginfo 0.14.3-4.el8 Red Hat Enterprise Linux AppStream (v. 8) spice 0.14.3-4.el8, spice-server 0.14.3-4.el8
    fixed: vendor fix RHSA-2021:1924

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

2.53% chance of exploitation in the next 30 days, higher than 84% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • blog.qualys.com https://blog.qualys.com/product-tech/2011/10/31/tls-renegotiation-and-denial-of-service-attacks referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P

Affected products

  • n/a spice

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.