CVE-2021-22956

mediumpriority · track · 30EPSS 0.009 · 60 %ileEURUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

0.92% (60th) EPSS

CVSS 4.3 · medium

Is it mine?

15 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · fstec_bdu · nvd

EPSS · scored 2026-10-26

An uncontrolled resource consumption vulnerability exists in Citrix ADC <13.0-83.27, <12.1-63.22 and 11.1-65.23 that could allow an attacker with access to NSIP or SNIP with management interface access to cause a temporary disruption of the Management GUI, Nitro API, and RPC communication.

cvss

Technical severity, 0–10. One row per scoring source.

7.5

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 4.3–7.5

v2.04.3mediumAV:N/AC:M/Au:N/C:N/I:N/A:Pprimary · NVD / NIST USexploitability 8.6 · impact 2.9

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 3.6

v3.17.5highAV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · FSTEC (BDU) RU

v3.16.9mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-400USprimaryCWE-400US

affected products (15)

Products and version ranges known to be affected.

n/a Citrix ADC, Citrix Gateway, Citrix SDWAN≤ Citrix ADC 11.1,12.1,13.0,13.1enisa_euvdEU
Citrix Systems Inc. Citrix ADC≤ 11.1-65.23fstec_bduRU
Citrix Systems Inc. Citrix ADC12.1 → 12.1-63.22fstec_bduRU
Citrix Systems Inc. Citrix ADC13.0 → 13.0-83.27fstec_bduRU
Citrix Systems Inc. Citrix Gateway≤ 11.1-65.23fstec_bduRU
Citrix Systems Inc. Citrix Gateway12.1 → 12.1-63.22fstec_bduRU
Citrix Systems Inc. Citrix Gateway13.0 → 13.0-83.27fstec_bduRU
citrix application delivery controller firmware< 11.1-65.23nvdUScpe:2.3:o:citrix:application_delivery_controller_firmware:*:*:*:*:*:*:*:*
citrix application delivery controller firmware12.1 → 12.1-63.22nvdUScpe:2.3:o:citrix:application_delivery_controller_firmware:*:*:*:*:*:*:*:*
citrix application delivery controller firmware13.0 → 13.0-83.27nvdUScpe:2.3:o:citrix:application_delivery_controller_firmware:*:*:*:*:*:*:*:*
citrix gateway< 11.1-65.23nvdUScpe:2.3:a:citrix:gateway:*:*:*:*:*:*:*:*
citrix gateway12.1 → 12.1-63.22nvdUScpe:2.3:a:citrix:gateway:*:*:*:*:*:*:*:*
citrix gateway13.0 → 13.0-65.23nvdUScpe:2.3:a:citrix:gateway:*:*:*:*:*:*:*:*
citrix sd-wan< 10.2.9cnvdUScpe:2.3:a:citrix:sd-wan:*:*:*:*:*:*:*:*
citrix sd-wan11.4.0 → 11.4.2nvdUScpe:2.3:a:citrix:sd-wan:*:*:*:*:*:*:*:*

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu nvd NVD CVE.org MITRE

published 2021-12-07modified 2026-06-17

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references (5)

External citations — patches, advisories, analysis.

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